Bluetooth: Remove the send_lock spinlock from ERTM
[cascardo/linux.git] / net / bluetooth / l2cap.c
index 1b682a5..dc8601f 100644 (file)
 
 #define VERSION "2.14"
 
-#ifdef CONFIG_BT_L2CAP_EXT_FEATURES
-static int enable_ertm = 1;
-#else
 static int enable_ertm = 0;
-#endif
-static int max_transmit = L2CAP_DEFAULT_MAX_TX;
-static int tx_window = L2CAP_DEFAULT_TX_WINDOW;
 
 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN;
 static u8 l2cap_fixed_chan[8] = { 0x02, };
@@ -278,6 +272,24 @@ static void l2cap_chan_del(struct sock *sk, int err)
                parent->sk_data_ready(parent, 0);
        } else
                sk->sk_state_change(sk);
+
+       skb_queue_purge(TX_QUEUE(sk));
+
+       if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) {
+               struct srej_list *l, *tmp;
+
+               del_timer(&l2cap_pi(sk)->retrans_timer);
+               del_timer(&l2cap_pi(sk)->monitor_timer);
+               del_timer(&l2cap_pi(sk)->ack_timer);
+
+               skb_queue_purge(SREJ_QUEUE(sk));
+               skb_queue_purge(BUSY_QUEUE(sk));
+
+               list_for_each_entry_safe(l, tmp, SREJ_LIST(sk), list) {
+                       list_del(&l->list);
+                       kfree(l);
+               }
+       }
 }
 
 /* Service level security */
@@ -351,8 +363,12 @@ static inline void l2cap_send_sframe(struct l2cap_pinfo *pi, u16 control)
        struct sk_buff *skb;
        struct l2cap_hdr *lh;
        struct l2cap_conn *conn = pi->conn;
+       struct sock *sk = (struct sock *)pi;
        int count, hlen = L2CAP_HDR_SIZE + 2;
 
+       if (sk->sk_state != BT_CONNECTED)
+               return;
+
        if (pi->fcs == L2CAP_FCS_CRC16)
                hlen += 2;
 
@@ -401,6 +417,11 @@ static inline void l2cap_send_rr_or_rnr(struct l2cap_pinfo *pi, u16 control)
        l2cap_send_sframe(pi, control);
 }
 
+static inline int __l2cap_no_conn_pending(struct sock *sk)
+{
+       return !(l2cap_pi(sk)->conf_state & L2CAP_CONF_CONNECT_PEND);
+}
+
 static void l2cap_do_start(struct sock *sk)
 {
        struct l2cap_conn *conn = l2cap_pi(sk)->conn;
@@ -409,12 +430,13 @@ static void l2cap_do_start(struct sock *sk)
                if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
                        return;
 
-               if (l2cap_check_security(sk)) {
+               if (l2cap_check_security(sk) && __l2cap_no_conn_pending(sk)) {
                        struct l2cap_conn_req req;
                        req.scid = cpu_to_le16(l2cap_pi(sk)->scid);
                        req.psm  = l2cap_pi(sk)->psm;
 
                        l2cap_pi(sk)->ident = l2cap_get_ident(conn);
+                       l2cap_pi(sk)->conf_state |= L2CAP_CONF_CONNECT_PEND;
 
                        l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
                                        L2CAP_CONN_REQ, sizeof(req), &req);
@@ -434,24 +456,57 @@ static void l2cap_do_start(struct sock *sk)
        }
 }
 
-static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct sock *sk)
+static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
+{
+       u32 local_feat_mask = l2cap_feat_mask;
+       if (enable_ertm)
+               local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
+
+       switch (mode) {
+       case L2CAP_MODE_ERTM:
+               return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
+       case L2CAP_MODE_STREAMING:
+               return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
+       default:
+               return 0x00;
+       }
+}
+
+static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct sock *sk, int err)
 {
        struct l2cap_disconn_req req;
 
+       if (!conn)
+               return;
+
+       skb_queue_purge(TX_QUEUE(sk));
+
+       if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) {
+               del_timer(&l2cap_pi(sk)->retrans_timer);
+               del_timer(&l2cap_pi(sk)->monitor_timer);
+               del_timer(&l2cap_pi(sk)->ack_timer);
+       }
+
        req.dcid = cpu_to_le16(l2cap_pi(sk)->dcid);
        req.scid = cpu_to_le16(l2cap_pi(sk)->scid);
        l2cap_send_cmd(conn, l2cap_get_ident(conn),
                        L2CAP_DISCONN_REQ, sizeof(req), &req);
+
+       sk->sk_state = BT_DISCONN;
+       sk->sk_err = err;
 }
 
 /* ---- L2CAP connections ---- */
 static void l2cap_conn_start(struct l2cap_conn *conn)
 {
        struct l2cap_chan_list *l = &conn->chan_list;
+       struct sock_del_list del, *tmp1, *tmp2;
        struct sock *sk;
 
        BT_DBG("conn %p", conn);
 
+       INIT_LIST_HEAD(&del.list);
+
        read_lock(&l->lock);
 
        for (sk = l->head; sk; sk = l2cap_pi(sk)->next_c) {
@@ -464,12 +519,27 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
                }
 
                if (sk->sk_state == BT_CONNECT) {
-                       if (l2cap_check_security(sk)) {
+                       if (l2cap_check_security(sk) &&
+                                       __l2cap_no_conn_pending(sk)) {
                                struct l2cap_conn_req req;
+
+                               if (!l2cap_mode_supported(l2cap_pi(sk)->mode,
+                                               conn->feat_mask)
+                                               && l2cap_pi(sk)->conf_state &
+                                               L2CAP_CONF_STATE2_DEVICE) {
+                                       tmp1 = kzalloc(sizeof(struct srej_list),
+                                                       GFP_ATOMIC);
+                                       tmp1->sk = sk;
+                                       list_add_tail(&tmp1->list, &del.list);
+                                       bh_unlock_sock(sk);
+                                       continue;
+                               }
+
                                req.scid = cpu_to_le16(l2cap_pi(sk)->scid);
                                req.psm  = l2cap_pi(sk)->psm;
 
                                l2cap_pi(sk)->ident = l2cap_get_ident(conn);
+                               l2cap_pi(sk)->conf_state |= L2CAP_CONF_CONNECT_PEND;
 
                                l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
                                        L2CAP_CONN_REQ, sizeof(req), &req);
@@ -504,6 +574,14 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
        }
 
        read_unlock(&l->lock);
+
+       list_for_each_entry_safe(tmp1, tmp2, &del.list, list) {
+               bh_lock_sock(tmp1->sk);
+               __l2cap_sock_close(tmp1->sk, ECONNRESET);
+               bh_unlock_sock(tmp1->sk);
+               list_del(&tmp1->list);
+               kfree(tmp1);
+       }
 }
 
 static void l2cap_conn_ready(struct l2cap_conn *conn)
@@ -732,9 +810,8 @@ static void __l2cap_sock_close(struct sock *sk, int reason)
                                sk->sk_type == SOCK_STREAM) {
                        struct l2cap_conn *conn = l2cap_pi(sk)->conn;
 
-                       sk->sk_state = BT_DISCONN;
                        l2cap_sock_set_timer(sk, sk->sk_sndtimeo);
-                       l2cap_send_disconn_req(conn, sk);
+                       l2cap_send_disconn_req(conn, sk, reason);
                } else
                        l2cap_chan_del(sk, reason);
                break;
@@ -794,6 +871,7 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
 
                pi->imtu = l2cap_pi(parent)->imtu;
                pi->omtu = l2cap_pi(parent)->omtu;
+               pi->conf_state = l2cap_pi(parent)->conf_state;
                pi->mode = l2cap_pi(parent)->mode;
                pi->fcs  = l2cap_pi(parent)->fcs;
                pi->max_tx = l2cap_pi(parent)->max_tx;
@@ -804,13 +882,15 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
        } else {
                pi->imtu = L2CAP_DEFAULT_MTU;
                pi->omtu = 0;
-               if (enable_ertm && sk->sk_type == SOCK_STREAM)
+               if (enable_ertm && sk->sk_type == SOCK_STREAM) {
                        pi->mode = L2CAP_MODE_ERTM;
-               else
+                       pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
+               } else {
                        pi->mode = L2CAP_MODE_BASIC;
-               pi->max_tx = max_transmit;
+               }
+               pi->max_tx = L2CAP_DEFAULT_MAX_TX;
                pi->fcs  = L2CAP_FCS_CRC16;
-               pi->tx_win = tx_window;
+               pi->tx_win = L2CAP_DEFAULT_TX_WINDOW;
                pi->sec_level = BT_SECURITY_LOW;
                pi->role_switch = 0;
                pi->force_reliable = 0;
@@ -1277,9 +1357,11 @@ static void l2cap_monitor_timeout(unsigned long arg)
 {
        struct sock *sk = (void *) arg;
 
+       BT_DBG("sk %p", sk);
+
        bh_lock_sock(sk);
        if (l2cap_pi(sk)->retry_count >= l2cap_pi(sk)->remote_max_tx) {
-               l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk);
+               l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk, ECONNABORTED);
                bh_unlock_sock(sk);
                return;
        }
@@ -1295,6 +1377,8 @@ static void l2cap_retrans_timeout(unsigned long arg)
 {
        struct sock *sk = (void *) arg;
 
+       BT_DBG("sk %p", sk);
+
        bh_lock_sock(sk);
        l2cap_pi(sk)->retry_count = 1;
        __mod_monitor_timer();
@@ -1387,15 +1471,22 @@ static void l2cap_retransmit_one_frame(struct sock *sk, u8 tx_seq)
 
        if (pi->remote_max_tx &&
                        bt_cb(skb)->retries == pi->remote_max_tx) {
-               l2cap_send_disconn_req(pi->conn, sk);
+               l2cap_send_disconn_req(pi->conn, sk, ECONNABORTED);
                return;
        }
 
        tx_skb = skb_clone(skb, GFP_ATOMIC);
        bt_cb(skb)->retries++;
        control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+
+       if (pi->conn_state & L2CAP_CONN_SEND_FBIT) {
+               control |= L2CAP_CTRL_FINAL;
+               pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
+       }
+
        control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT)
                        | (tx_seq << L2CAP_CTRL_TXSEQ_SHIFT);
+
        put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
 
        if (pi->fcs == L2CAP_FCS_CRC16) {
@@ -1413,15 +1504,14 @@ static int l2cap_ertm_send(struct sock *sk)
        u16 control, fcs;
        int nsent = 0;
 
-       if (pi->conn_state & L2CAP_CONN_WAIT_F)
-               return 0;
+       if (sk->sk_state != BT_CONNECTED)
+               return -ENOTCONN;
 
-       while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk)) &&
-                       !(pi->conn_state & L2CAP_CONN_REMOTE_BUSY)) {
+       while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk))) {
 
                if (pi->remote_max_tx &&
                                bt_cb(skb)->retries == pi->remote_max_tx) {
-                       l2cap_send_disconn_req(pi->conn, sk);
+                       l2cap_send_disconn_req(pi->conn, sk, ECONNABORTED);
                        break;
                }
 
@@ -1430,6 +1520,8 @@ static int l2cap_ertm_send(struct sock *sk)
                bt_cb(skb)->retries++;
 
                control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+               control &= L2CAP_CTRL_SAR;
+
                if (pi->conn_state & L2CAP_CONN_SEND_FBIT) {
                        control |= L2CAP_CTRL_FINAL;
                        pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
@@ -1470,16 +1562,11 @@ static int l2cap_retransmit_frames(struct sock *sk)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        int ret;
 
-       spin_lock_bh(&pi->send_lock);
-
        if (!skb_queue_empty(TX_QUEUE(sk)))
                sk->sk_send_head = TX_QUEUE(sk)->next;
 
        pi->next_tx_seq = pi->expected_ack_seq;
        ret = l2cap_ertm_send(sk);
-
-       spin_unlock_bh(&pi->send_lock);
-
        return ret;
 }
 
@@ -1487,7 +1574,6 @@ static void l2cap_send_ack(struct l2cap_pinfo *pi)
 {
        struct sock *sk = (struct sock *)pi;
        u16 control = 0;
-       int nframes;
 
        control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
 
@@ -1498,11 +1584,7 @@ static void l2cap_send_ack(struct l2cap_pinfo *pi)
                return;
        }
 
-       spin_lock_bh(&pi->send_lock);
-       nframes = l2cap_ertm_send(sk);
-       spin_unlock_bh(&pi->send_lock);
-
-       if (nframes > 0)
+       if (l2cap_ertm_send(sk) > 0)
                return;
 
        control |= L2CAP_SUPER_RCV_READY;
@@ -1697,10 +1779,8 @@ static inline int l2cap_sar_segment_sdu(struct sock *sk, struct msghdr *msg, siz
                size += buflen;
        }
        skb_queue_splice_tail(&sar_queue, TX_QUEUE(sk));
-       spin_lock_bh(&pi->send_lock);
        if (sk->sk_send_head == NULL)
                sk->sk_send_head = sar_queue.next;
-       spin_unlock_bh(&pi->send_lock);
 
        return size;
 }
@@ -1772,14 +1852,9 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
                        }
                        __skb_queue_tail(TX_QUEUE(sk), skb);
 
-                       if (pi->mode == L2CAP_MODE_ERTM)
-                               spin_lock_bh(&pi->send_lock);
-
                        if (sk->sk_send_head == NULL)
                                sk->sk_send_head = skb;
 
-                       if (pi->mode == L2CAP_MODE_ERTM)
-                               spin_unlock_bh(&pi->send_lock);
                } else {
                /* Segment SDU into multiples PDUs */
                        err = l2cap_sar_segment_sdu(sk, msg, len);
@@ -1790,9 +1865,12 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
                if (pi->mode == L2CAP_MODE_STREAMING) {
                        err = l2cap_streaming_send(sk);
                } else {
-                       spin_lock_bh(&pi->send_lock);
+                       if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY &&
+                                       pi->conn_state && L2CAP_CONN_WAIT_F) {
+                               err = len;
+                               break;
+                       }
                        err = l2cap_ertm_send(sk);
-                       spin_unlock_bh(&pi->send_lock);
                }
 
                if (err >= 0)
@@ -1863,9 +1941,15 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
                        break;
                }
 
+               if (opts.txwin_size > L2CAP_DEFAULT_TX_WINDOW) {
+                       err = -EINVAL;
+                       break;
+               }
+
                l2cap_pi(sk)->mode = opts.mode;
                switch (l2cap_pi(sk)->mode) {
                case L2CAP_MODE_BASIC:
+                       l2cap_pi(sk)->conf_state &= ~L2CAP_CONF_STATE2_DEVICE;
                        break;
                case L2CAP_MODE_ERTM:
                case L2CAP_MODE_STREAMING:
@@ -2137,6 +2221,10 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
                        err = bt_sock_wait_state(sk, BT_CLOSED,
                                                        sk->sk_lingertime);
        }
+
+       if (!err && sk->sk_err)
+               err = -sk->sk_err;
+
        release_sock(sk);
        return err;
 }
@@ -2357,27 +2445,10 @@ static inline void l2cap_ertm_init(struct sock *sk)
 
        __skb_queue_head_init(SREJ_QUEUE(sk));
        __skb_queue_head_init(BUSY_QUEUE(sk));
-       spin_lock_init(&l2cap_pi(sk)->send_lock);
 
        INIT_WORK(&l2cap_pi(sk)->busy_work, l2cap_busy_work);
 }
 
-static int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
-{
-       u32 local_feat_mask = l2cap_feat_mask;
-       if (enable_ertm)
-               local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
-
-       switch (mode) {
-       case L2CAP_MODE_ERTM:
-               return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
-       case L2CAP_MODE_STREAMING:
-               return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
-       default:
-               return 0x00;
-       }
-}
-
 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
 {
        switch (mode) {
@@ -2406,10 +2477,10 @@ static int l2cap_build_conf_req(struct sock *sk, void *data)
        switch (pi->mode) {
        case L2CAP_MODE_STREAMING:
        case L2CAP_MODE_ERTM:
-               pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
-               if (!l2cap_mode_supported(pi->mode, pi->conn->feat_mask))
-                       l2cap_send_disconn_req(pi->conn, sk);
-               break;
+               if (pi->conf_state & L2CAP_CONF_STATE2_DEVICE)
+                       break;
+
+               /* fall through */
        default:
                pi->mode = l2cap_select_mode(rfc.mode, pi->conn->feat_mask);
                break;
@@ -2420,6 +2491,14 @@ done:
        case L2CAP_MODE_BASIC:
                if (pi->imtu != L2CAP_DEFAULT_MTU)
                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
+
+               rfc.mode            = L2CAP_MODE_BASIC;
+               rfc.txwin_size      = 0;
+               rfc.max_transmit    = 0;
+               rfc.retrans_timeout = 0;
+               rfc.monitor_timeout = 0;
+               rfc.max_pdu_size    = 0;
+
                break;
 
        case L2CAP_MODE_ERTM:
@@ -2432,9 +2511,6 @@ done:
                if (L2CAP_DEFAULT_MAX_PDU_SIZE > pi->conn->mtu - 10)
                        rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
-               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
-                                       sizeof(rfc), (unsigned long) &rfc);
-
                if (!(pi->conn->feat_mask & L2CAP_FEAT_FCS))
                        break;
 
@@ -2455,9 +2531,6 @@ done:
                if (L2CAP_DEFAULT_MAX_PDU_SIZE > pi->conn->mtu - 10)
                        rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
-               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
-                                       sizeof(rfc), (unsigned long) &rfc);
-
                if (!(pi->conn->feat_mask & L2CAP_FEAT_FCS))
                        break;
 
@@ -2469,6 +2542,9 @@ done:
                break;
        }
 
+       l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+                                               (unsigned long) &rfc);
+
        /* FIXME: Need actual value of the flush timeout */
        //if (flush_to != L2CAP_DEFAULT_FLUSH_TO)
        //   l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2, pi->flush_to);
@@ -2539,12 +2615,15 @@ static int l2cap_parse_conf_req(struct sock *sk, void *data)
        switch (pi->mode) {
        case L2CAP_MODE_STREAMING:
        case L2CAP_MODE_ERTM:
-               pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
-               if (!l2cap_mode_supported(pi->mode, pi->conn->feat_mask))
+               if (!(pi->conf_state & L2CAP_CONF_STATE2_DEVICE)) {
+                       pi->mode = l2cap_select_mode(rfc.mode,
+                                       pi->conn->feat_mask);
+                       break;
+               }
+
+               if (pi->mode != rfc.mode)
                        return -ECONNREFUSED;
-               break;
-       default:
-               pi->mode = l2cap_select_mode(rfc.mode, pi->conn->feat_mask);
+
                break;
        }
 
@@ -2667,7 +2746,6 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data,
                                                        rfc.mode != pi->mode)
                                return -ECONNREFUSED;
 
-                       pi->mode = rfc.mode;
                        pi->fcs = 0;
 
                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
@@ -2676,6 +2754,11 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data,
                }
        }
 
+       if (pi->mode == L2CAP_MODE_BASIC && pi->mode != rfc.mode)
+               return -ECONNREFUSED;
+
+       pi->mode = rfc.mode;
+
        if (*result == L2CAP_CONF_SUCCESS) {
                switch (rfc.mode) {
                case L2CAP_MODE_ERTM:
@@ -2912,7 +2995,6 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
                l2cap_pi(sk)->ident = 0;
                l2cap_pi(sk)->dcid = dcid;
                l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
-
                l2cap_pi(sk)->conf_state &= ~L2CAP_CONF_CONNECT_PEND;
 
                l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
@@ -2950,8 +3032,14 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        if (!sk)
                return -ENOENT;
 
-       if (sk->sk_state == BT_DISCONN)
+       if (sk->sk_state != BT_CONFIG) {
+               struct l2cap_cmd_rej rej;
+
+               rej.reason = cpu_to_le16(0x0002);
+               l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
+                               sizeof(rej), &rej);
                goto unlock;
+       }
 
        /* Reject if config buffer is too small. */
        len = cmd_len - sizeof(*req);
@@ -2977,7 +3065,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        /* Complete config. */
        len = l2cap_parse_conf_req(sk, rsp);
        if (len < 0) {
-               l2cap_send_disconn_req(conn, sk);
+               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                goto unlock;
        }
 
@@ -3047,7 +3135,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
                        char req[64];
 
                        if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
-                               l2cap_send_disconn_req(conn, sk);
+                               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                                goto done;
                        }
 
@@ -3056,7 +3144,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
                        len = l2cap_parse_conf_rsp(sk, rsp->data,
                                                        len, req, &result);
                        if (len < 0) {
-                               l2cap_send_disconn_req(conn, sk);
+                               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                                goto done;
                        }
 
@@ -3069,10 +3157,9 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
                }
 
        default:
-               sk->sk_state = BT_DISCONN;
                sk->sk_err = ECONNRESET;
                l2cap_sock_set_timer(sk, HZ * 5);
-               l2cap_send_disconn_req(conn, sk);
+               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                goto done;
        }
 
@@ -3123,16 +3210,6 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 
        sk->sk_shutdown = SHUTDOWN_MASK;
 
-       skb_queue_purge(TX_QUEUE(sk));
-
-       if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) {
-               skb_queue_purge(SREJ_QUEUE(sk));
-               skb_queue_purge(BUSY_QUEUE(sk));
-               del_timer(&l2cap_pi(sk)->retrans_timer);
-               del_timer(&l2cap_pi(sk)->monitor_timer);
-               del_timer(&l2cap_pi(sk)->ack_timer);
-       }
-
        l2cap_chan_del(sk, ECONNRESET);
        bh_unlock_sock(sk);
 
@@ -3155,16 +3232,6 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
        if (!sk)
                return 0;
 
-       skb_queue_purge(TX_QUEUE(sk));
-
-       if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) {
-               skb_queue_purge(SREJ_QUEUE(sk));
-               skb_queue_purge(BUSY_QUEUE(sk));
-               del_timer(&l2cap_pi(sk)->retrans_timer);
-               del_timer(&l2cap_pi(sk)->monitor_timer);
-               del_timer(&l2cap_pi(sk)->ack_timer);
-       }
-
        l2cap_chan_del(sk, 0);
        bh_unlock_sock(sk);
 
@@ -3363,25 +3430,19 @@ static inline void l2cap_send_i_or_rr_or_rnr(struct sock *sk)
        u16 control = 0;
 
        pi->frames_sent = 0;
-       pi->conn_state |= L2CAP_CONN_SEND_FBIT;
 
        control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
 
        if (pi->conn_state & L2CAP_CONN_LOCAL_BUSY) {
-               control |= L2CAP_SUPER_RCV_NOT_READY | L2CAP_CTRL_FINAL;
+               control |= L2CAP_SUPER_RCV_NOT_READY;
                l2cap_send_sframe(pi, control);
                pi->conn_state |= L2CAP_CONN_RNR_SENT;
-               pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
        }
 
-       if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY && pi->unacked_frames > 0)
-               __mod_retrans_timer();
-
-       pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
+       if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY)
+               l2cap_retransmit_frames(sk);
 
-       spin_lock_bh(&pi->send_lock);
        l2cap_ertm_send(sk);
-       spin_unlock_bh(&pi->send_lock);
 
        if (!(pi->conn_state & L2CAP_CONN_LOCAL_BUSY) &&
                        pi->frames_sent == 0) {
@@ -3393,6 +3454,8 @@ static inline void l2cap_send_i_or_rr_or_rnr(struct sock *sk)
 static int l2cap_add_to_srej_queue(struct sock *sk, struct sk_buff *skb, u8 tx_seq, u8 sar)
 {
        struct sk_buff *next_skb;
+       struct l2cap_pinfo *pi = l2cap_pi(sk);
+       int tx_seq_offset, next_tx_seq_offset;
 
        bt_cb(skb)->tx_seq = tx_seq;
        bt_cb(skb)->sar = sar;
@@ -3403,11 +3466,20 @@ static int l2cap_add_to_srej_queue(struct sock *sk, struct sk_buff *skb, u8 tx_s
                return 0;
        }
 
+       tx_seq_offset = (tx_seq - pi->buffer_seq) % 64;
+       if (tx_seq_offset < 0)
+               tx_seq_offset += 64;
+
        do {
                if (bt_cb(next_skb)->tx_seq == tx_seq)
                        return -EINVAL;
 
-               if (bt_cb(next_skb)->tx_seq > tx_seq) {
+               next_tx_seq_offset = (bt_cb(next_skb)->tx_seq -
+                                               pi->buffer_seq) % 64;
+               if (next_tx_seq_offset < 0)
+                       next_tx_seq_offset += 64;
+
+               if (next_tx_seq_offset > tx_seq_offset) {
                        __skb_queue_before(SREJ_QUEUE(sk), next_skb, skb);
                        return 0;
                }
@@ -3525,7 +3597,7 @@ drop:
        pi->sdu = NULL;
 
 disconnect:
-       l2cap_send_disconn_req(pi->conn, sk);
+       l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
        kfree_skb(skb);
        return 0;
 }
@@ -3548,7 +3620,7 @@ static void l2cap_busy_work(struct work_struct *work)
 
                if (n_tries++ > L2CAP_LOCAL_BUSY_TRIES) {
                        err = -EBUSY;
-                       l2cap_send_disconn_req(pi->conn, sk);
+                       l2cap_send_disconn_req(pi->conn, sk, EBUSY);
                        goto done;
                }
 
@@ -3600,6 +3672,8 @@ done:
        pi->conn_state &= ~L2CAP_CONN_LOCAL_BUSY;
        pi->conn_state &= ~L2CAP_CONN_RNR_SENT;
 
+       BT_DBG("sk %p, Exit local busy", sk);
+
        set_current_state(TASK_RUNNING);
        remove_wait_queue(sk_sleep(sk), &wait);
 
@@ -3624,6 +3698,8 @@ static int l2cap_push_rx_skb(struct sock *sk, struct sk_buff *skb, u16 control)
        }
 
        /* Busy Condition */
+       BT_DBG("sk %p, Enter local busy", sk);
+
        pi->conn_state |= L2CAP_CONN_LOCAL_BUSY;
        bt_cb(skb)->sar = control >> L2CAP_CTRL_SAR_SHIFT;
        __skb_queue_tail(BUSY_QUEUE(sk), skb);
@@ -3634,6 +3710,8 @@ static int l2cap_push_rx_skb(struct sock *sk, struct sk_buff *skb, u16 control)
 
        pi->conn_state |= L2CAP_CONN_RNR_SENT;
 
+       del_timer(&pi->ack_timer);
+
        queue_work(_busy_wq, &pi->busy_work);
 
        return err;
@@ -3747,7 +3825,7 @@ static void l2cap_check_srej_gap(struct sock *sk, u8 tx_seq)
                l2cap_ertm_reassembly_sdu(sk, skb, control);
                l2cap_pi(sk)->buffer_seq_srej =
                        (l2cap_pi(sk)->buffer_seq_srej + 1) % 64;
-               tx_seq++;
+               tx_seq = (tx_seq + 1) % 64;
        }
 }
 
@@ -3783,10 +3861,11 @@ static void l2cap_send_srejframe(struct sock *sk, u8 tx_seq)
                l2cap_send_sframe(pi, control);
 
                new = kzalloc(sizeof(struct srej_list), GFP_ATOMIC);
-               new->tx_seq = pi->expected_tx_seq++;
+               new->tx_seq = pi->expected_tx_seq;
+               pi->expected_tx_seq = (pi->expected_tx_seq + 1) % 64;
                list_add_tail(&new->list, SREJ_LIST(sk));
        }
-       pi->expected_tx_seq++;
+       pi->expected_tx_seq = (pi->expected_tx_seq + 1) % 64;
 }
 
 static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, struct sk_buff *skb)
@@ -3795,11 +3874,12 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
        u8 tx_seq = __get_txseq(rx_control);
        u8 req_seq = __get_reqseq(rx_control);
        u8 sar = rx_control >> L2CAP_CTRL_SAR_SHIFT;
-       u8 tx_seq_offset, expected_tx_seq_offset;
+       int tx_seq_offset, expected_tx_seq_offset;
        int num_to_ack = (pi->tx_win/6) + 1;
        int err = 0;
 
-       BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len);
+       BT_DBG("sk %p len %d tx_seq %d rx_control 0x%4.4x", sk, skb->len, tx_seq,
+                                                               rx_control);
 
        if (L2CAP_CTRL_FINAL & rx_control &&
                        l2cap_pi(sk)->conn_state & L2CAP_CONN_WAIT_F) {
@@ -3821,7 +3901,7 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
 
        /* invalid tx_seq */
        if (tx_seq_offset >= pi->tx_win) {
-               l2cap_send_disconn_req(pi->conn, sk);
+               l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
                goto drop;
        }
 
@@ -3844,6 +3924,7 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
                                pi->buffer_seq = pi->buffer_seq_srej;
                                pi->conn_state &= ~L2CAP_CONN_SREJ_SENT;
                                l2cap_send_ack(pi);
+                               BT_DBG("sk %p, Exit SREJ_SENT", sk);
                        }
                } else {
                        struct srej_list *l;
@@ -3872,6 +3953,8 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
 
                pi->conn_state |= L2CAP_CONN_SREJ_SENT;
 
+               BT_DBG("sk %p, Enter SREJ", sk);
+
                INIT_LIST_HEAD(SREJ_LIST(sk));
                pi->buffer_seq_srej = pi->buffer_seq;
 
@@ -3882,6 +3965,8 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
                pi->conn_state |= L2CAP_CONN_SEND_PBIT;
 
                l2cap_send_srejframe(sk, tx_seq);
+
+               del_timer(&pi->ack_timer);
        }
        return 0;
 
@@ -3895,6 +3980,10 @@ expected:
                return 0;
        }
 
+       err = l2cap_push_rx_skb(sk, skb, rx_control);
+       if (err < 0)
+               return 0;
+
        if (rx_control & L2CAP_CTRL_FINAL) {
                if (pi->conn_state & L2CAP_CONN_REJ_ACT)
                        pi->conn_state &= ~L2CAP_CONN_REJ_ACT;
@@ -3902,10 +3991,6 @@ expected:
                        l2cap_retransmit_frames(sk);
        }
 
-       err = l2cap_push_rx_skb(sk, skb, rx_control);
-       if (err < 0)
-               return 0;
-
        __mod_ack_timer();
 
        pi->num_acked = (pi->num_acked + 1) % num_to_ack;
@@ -3923,10 +4008,14 @@ static inline void l2cap_data_channel_rrframe(struct sock *sk, u16 rx_control)
 {
        struct l2cap_pinfo *pi = l2cap_pi(sk);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, __get_reqseq(rx_control),
+                                               rx_control);
+
        pi->expected_ack_seq = __get_reqseq(rx_control);
        l2cap_drop_acked_frames(sk);
 
        if (rx_control & L2CAP_CTRL_POLL) {
+               pi->conn_state |= L2CAP_CONN_SEND_FBIT;
                if (pi->conn_state & L2CAP_CONN_SREJ_SENT) {
                        if ((pi->conn_state & L2CAP_CONN_REMOTE_BUSY) &&
                                        (pi->unacked_frames > 0))
@@ -3955,9 +4044,7 @@ static inline void l2cap_data_channel_rrframe(struct sock *sk, u16 rx_control)
                if (pi->conn_state & L2CAP_CONN_SREJ_SENT) {
                        l2cap_send_ack(pi);
                } else {
-                       spin_lock_bh(&pi->send_lock);
                        l2cap_ertm_send(sk);
-                       spin_unlock_bh(&pi->send_lock);
                }
        }
 }
@@ -3967,6 +4054,8 @@ static inline void l2cap_data_channel_rejframe(struct sock *sk, u16 rx_control)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_reqseq(rx_control);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, tx_seq, rx_control);
+
        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
 
        pi->expected_ack_seq = tx_seq;
@@ -3989,16 +4078,18 @@ static inline void l2cap_data_channel_srejframe(struct sock *sk, u16 rx_control)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_reqseq(rx_control);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, tx_seq, rx_control);
+
        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
 
        if (rx_control & L2CAP_CTRL_POLL) {
                pi->expected_ack_seq = tx_seq;
                l2cap_drop_acked_frames(sk);
+
+               pi->conn_state |= L2CAP_CONN_SEND_FBIT;
                l2cap_retransmit_one_frame(sk, tx_seq);
 
-               spin_lock_bh(&pi->send_lock);
                l2cap_ertm_send(sk);
-               spin_unlock_bh(&pi->send_lock);
 
                if (pi->conn_state & L2CAP_CONN_WAIT_F) {
                        pi->srej_save_reqseq = tx_seq;
@@ -4024,10 +4115,15 @@ static inline void l2cap_data_channel_rnrframe(struct sock *sk, u16 rx_control)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_reqseq(rx_control);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, tx_seq, rx_control);
+
        pi->conn_state |= L2CAP_CONN_REMOTE_BUSY;
        pi->expected_ack_seq = tx_seq;
        l2cap_drop_acked_frames(sk);
 
+       if (rx_control & L2CAP_CTRL_POLL)
+               pi->conn_state |= L2CAP_CONN_SEND_FBIT;
+
        if (!(pi->conn_state & L2CAP_CONN_SREJ_SENT)) {
                del_timer(&pi->retrans_timer);
                if (rx_control & L2CAP_CTRL_POLL)
@@ -4079,8 +4175,9 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
 {
        struct sock *sk;
        struct l2cap_pinfo *pi;
-       u16 control, len;
-       u8 tx_seq, req_seq, next_tx_seq_offset, req_seq_offset;
+       u16 control;
+       u8 tx_seq, req_seq;
+       int len, next_tx_seq_offset, req_seq_offset;
 
        sk = l2cap_get_chan_by_scid(&conn->chan_list, cid);
        if (!sk) {
@@ -4114,24 +4211,24 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
                skb_pull(skb, 2);
                len = skb->len;
 
-               if (__is_sar_start(control))
-                       len -= 2;
-
-               if (pi->fcs == L2CAP_FCS_CRC16)
-                       len -= 2;
-
                /*
                 * We can just drop the corrupted I-frame here.
                 * Receiver will miss it and start proper recovery
                 * procedures and ask retransmission.
                 */
-               if (len > pi->mps) {
-                       l2cap_send_disconn_req(pi->conn, sk);
+               if (l2cap_check_fcs(pi, skb))
                        goto drop;
-               }
 
-               if (l2cap_check_fcs(pi, skb))
+               if (__is_sar_start(control) && __is_iframe(control))
+                       len -= 2;
+
+               if (pi->fcs == L2CAP_FCS_CRC16)
+                       len -= 2;
+
+               if (len > pi->mps) {
+                       l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
                        goto drop;
+               }
 
                req_seq = __get_reqseq(control);
                req_seq_offset = (req_seq - pi->expected_ack_seq) % 64;
@@ -4145,20 +4242,20 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
 
                /* check for invalid req-seq */
                if (req_seq_offset > next_tx_seq_offset) {
-                       l2cap_send_disconn_req(pi->conn, sk);
+                       l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
                        goto drop;
                }
 
                if (__is_iframe(control)) {
-                       if (len < 4) {
-                               l2cap_send_disconn_req(pi->conn, sk);
+                       if (len < 0) {
+                               l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
                                goto drop;
                        }
 
                        l2cap_data_channel_iframe(sk, control, skb);
                } else {
                        if (len != 0) {
-                               l2cap_send_disconn_req(pi->conn, sk);
+                               l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
                                goto drop;
                        }
 
@@ -4172,16 +4269,16 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
                skb_pull(skb, 2);
                len = skb->len;
 
+               if (l2cap_check_fcs(pi, skb))
+                       goto drop;
+
                if (__is_sar_start(control))
                        len -= 2;
 
                if (pi->fcs == L2CAP_FCS_CRC16)
                        len -= 2;
 
-               if (len > pi->mps || len < 4 || __is_sframe(control))
-                       goto drop;
-
-               if (l2cap_check_fcs(pi, skb))
+               if (len > pi->mps || len < 0 || __is_sframe(control))
                        goto drop;
 
                tx_seq = __get_txseq(control);
@@ -4404,6 +4501,7 @@ static int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
                                req.psm  = l2cap_pi(sk)->psm;
 
                                l2cap_pi(sk)->ident = l2cap_get_ident(conn);
+                               l2cap_pi(sk)->conf_state |= L2CAP_CONF_CONNECT_PEND;
 
                                l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
                                        L2CAP_CONN_REQ, sizeof(req), &req);
@@ -4674,12 +4772,6 @@ module_exit(l2cap_exit);
 module_param(enable_ertm, bool, 0644);
 MODULE_PARM_DESC(enable_ertm, "Enable enhanced retransmission mode");
 
-module_param(max_transmit, uint, 0644);
-MODULE_PARM_DESC(max_transmit, "Max transmit value (default = 3)");
-
-module_param(tx_window, uint, 0644);
-MODULE_PARM_DESC(tx_window, "Transmission window size value (default = 63)");
-
 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 MODULE_DESCRIPTION("Bluetooth L2CAP ver " VERSION);
 MODULE_VERSION(VERSION);