Merge upstream QEMU 10.0.50 into the Android source tree.

This change integrates many changes from the upstream QEMU sources.
Its main purpose is to enable correct ARMv6 and ARMv7 support to the
Android emulator. Due to the nature of the upstream code base, this
unfortunately also required changes to many other parts of the source.

Note that to ensure easier integrations in the future, some source files
and directories that have heavy Android-specific customization have been
renamed with an -android suffix. The original files are still there for
easier integration tracking, but *never* compiled. For example:

  net.c        net-android.c
  qemu-char.c  qemu-char-android.c
  slirp/       slirp-android/
  etc...

Tested on linux-x86, darwin-x86 and windows host machines.

1 files changed, 1364 insertions, 0 deletions

diff --git a/hw/bt-l2cap.c b/hw/bt-l2cap.c
new file mode 100644
index 0000000..b22b761
--- /dev/null
+++ b/hw/bt-l2cap.c
@@ -0,0 +1,1364 @@
+/*
+ * QEMU Bluetooth L2CAP logic.
+ *
+ * Copyright (C) 2008 Andrzej Zaborowski  <balrog@zabor.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA  02110-1301  USA
+ */
+
+#include "qemu-common.h"
+#include "qemu-timer.h"
+#include "bt.h"
+
+#define L2CAP_CID_MAX	0x100	/* Between 0x40 and 0x10000 */
+
+struct l2cap_instance_s {
+    struct bt_link_s *link;
+    struct bt_l2cap_device_s *dev;
+    int role;
+
+    uint8_t frame_in[65535 + L2CAP_HDR_SIZE] __attribute__ ((aligned (4)));
+    int frame_in_len;
+
+    uint8_t frame_out[65535 + L2CAP_HDR_SIZE] __attribute__ ((aligned (4)));
+    int frame_out_len;
+
+    /* Signalling channel timers.  They exist per-request but we can make
+     * sure we have no more than one outstanding request at any time.  */
+    QEMUTimer *rtx;
+    QEMUTimer *ertx;
+
+    int last_id;
+    int next_id;
+
+    struct l2cap_chan_s {
+        struct bt_l2cap_conn_params_s params;
+
+        void (*frame_in)(struct l2cap_chan_s *chan, uint16_t cid,
+                        const l2cap_hdr *hdr, int len);
+        int mps;
+        int min_mtu;
+
+        struct l2cap_instance_s *l2cap;
+
+        /* Only allocated channels */
+        uint16_t remote_cid;
+#define L2CAP_CFG_INIT	2
+#define L2CAP_CFG_ACC	1
+        int config_req_id; /* TODO: handle outgoing requests generically */
+        int config;
+
+        /* Only connection-oriented channels.  Note: if we allow the tx and
+         * rx traffic to be in different modes at any time, we need two.  */
+        int mode;
+
+        /* Only flow-controlled, connection-oriented channels */
+        uint8_t sdu[65536]; /* TODO: dynamically allocate */
+        int len_cur, len_total;
+        int rexmit;
+        int monitor_timeout;
+        QEMUTimer *monitor_timer;
+        QEMUTimer *retransmission_timer;
+    } *cid[L2CAP_CID_MAX];
+    /* The channel state machine states map as following:
+     * CLOSED           -> !cid[N]
+     * WAIT_CONNECT     -> never occurs
+     * WAIT_CONNECT_RSP -> never occurs
+     * CONFIG           -> cid[N] && config < 3
+     *   WAIT_CONFIG         -> never occurs, cid[N] && config == 0 && !config_r
+     *   WAIT_SEND_CONFIG    -> never occurs, cid[N] && config == 1 && !config_r
+     *   WAIT_CONFIG_REQ_RSP -> cid[N] && config == 0 && config_req_id
+     *   WAIT_CONFIG_RSP     -> cid[N] && config == 1 && config_req_id
+     *   WAIT_CONFIG_REQ     -> cid[N] && config == 2
+     * OPEN             -> cid[N] && config == 3
+     * WAIT_DISCONNECT  -> never occurs
+     */
+
+    struct l2cap_chan_s signalling_ch;
+    struct l2cap_chan_s group_ch;
+};
+
+struct slave_l2cap_instance_s {
+    struct bt_link_s link;	/* Underlying logical link (ACL) */
+    struct l2cap_instance_s l2cap;
+};
+
+struct bt_l2cap_psm_s {
+    int psm;
+    int min_mtu;
+    int (*new_channel)(struct bt_l2cap_device_s *device,
+                    struct bt_l2cap_conn_params_s *params);
+    struct bt_l2cap_psm_s *next;
+};
+
+static const uint16_t l2cap_fcs16_table[256] = {
+    0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241,
+    0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440,
+    0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40,
+    0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841,
+    0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40,
+    0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41,
+    0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641,
+    0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040,
+    0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240,
+    0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441,
+    0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41,
+    0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840,
+    0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41,
+    0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40,
+    0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640,
+    0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041,
+    0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240,
+    0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441,
+    0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41,
+    0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840,
+    0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41,
+    0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40,
+    0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640,
+    0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041,
+    0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241,
+    0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440,
+    0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40,
+    0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841,
+    0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40,
+    0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41,
+    0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641,
+    0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040,
+};
+
+static uint16_t l2cap_fcs16(const uint8_t *message, int len)
+{
+    uint16_t fcs = 0x0000;
+
+    while (len --)
+#if 0
+    {
+        int i;
+
+        fcs ^= *message ++;
+        for (i = 8; i; -- i)
+            if (fcs & 1)
+                fcs = (fcs >> 1) ^ 0xa001;
+            else
+                fcs = (fcs >> 1);
+    }
+#else
+        fcs = (fcs >> 8) ^ l2cap_fcs16_table[(fcs ^ *message ++) & 0xff];
+#endif
+
+    return fcs;
+}
+
+/* L2CAP layer logic (protocol) */
+
+static void l2cap_retransmission_timer_update(struct l2cap_chan_s *ch)
+{
+#if 0
+    if (ch->mode != L2CAP_MODE_BASIC && ch->rexmit)
+        qemu_mod_timer(ch->retransmission_timer);
+    else
+        qemu_del_timer(ch->retransmission_timer);
+#endif
+}
+
+static void l2cap_monitor_timer_update(struct l2cap_chan_s *ch)
+{
+#if 0
+    if (ch->mode != L2CAP_MODE_BASIC && !ch->rexmit)
+        qemu_mod_timer(ch->monitor_timer);
+    else
+        qemu_del_timer(ch->monitor_timer);
+#endif
+}
+
+static void l2cap_command_reject(struct l2cap_instance_s *l2cap, int id,
+                uint16_t reason, const void *data, int plen)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    l2cap_cmd_rej *params;
+    uint16_t len;
+
+    reason = cpu_to_le16(reason);
+    len = cpu_to_le16(L2CAP_CMD_REJ_SIZE + plen);
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + L2CAP_CMD_REJ_SIZE + plen);
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    hdr->code = L2CAP_COMMAND_REJ;
+    hdr->ident = id;
+    memcpy(&hdr->len, &len, sizeof(hdr->len));
+    memcpy(&params->reason, &reason, sizeof(reason));
+    if (plen)
+       memcpy(pkt + L2CAP_CMD_HDR_SIZE + L2CAP_CMD_REJ_SIZE, data, plen);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static void l2cap_command_reject_cid(struct l2cap_instance_s *l2cap, int id,
+                uint16_t reason, uint16_t dcid, uint16_t scid)
+{
+    l2cap_cmd_rej_cid params = {
+        .dcid = dcid,
+        .scid = scid,
+    };
+
+    l2cap_command_reject(l2cap, id, reason, &params, L2CAP_CMD_REJ_CID_SIZE);
+}
+
+static void l2cap_connection_response(struct l2cap_instance_s *l2cap,
+                int dcid, int scid, int result, int status)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    l2cap_conn_rsp *params;
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + L2CAP_CONN_RSP_SIZE);
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    hdr->code = L2CAP_CONN_RSP;
+    hdr->ident = l2cap->last_id;
+    hdr->len = cpu_to_le16(L2CAP_CONN_RSP_SIZE);
+
+    params->dcid = cpu_to_le16(dcid);
+    params->scid = cpu_to_le16(scid);
+    params->result = cpu_to_le16(result);
+    params->status = cpu_to_le16(status);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static void l2cap_configuration_request(struct l2cap_instance_s *l2cap,
+                int dcid, int flag, const uint8_t *data, int len)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    l2cap_conf_req *params;
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + L2CAP_CONF_REQ_SIZE(len));
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    /* TODO: unify the id sequencing */
+    l2cap->last_id = l2cap->next_id;
+    l2cap->next_id = l2cap->next_id == 255 ? 1 : l2cap->next_id + 1;
+
+    hdr->code = L2CAP_CONF_REQ;
+    hdr->ident = l2cap->last_id;
+    hdr->len = cpu_to_le16(L2CAP_CONF_REQ_SIZE(len));
+
+    params->dcid = cpu_to_le16(dcid);
+    params->flags = cpu_to_le16(flag);
+    if (len)
+        memcpy(params->data, data, len);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static void l2cap_configuration_response(struct l2cap_instance_s *l2cap,
+                int scid, int flag, int result, const uint8_t *data, int len)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    l2cap_conf_rsp *params;
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + L2CAP_CONF_RSP_SIZE(len));
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    hdr->code = L2CAP_CONF_RSP;
+    hdr->ident = l2cap->last_id;
+    hdr->len = cpu_to_le16(L2CAP_CONF_RSP_SIZE(len));
+
+    params->scid = cpu_to_le16(scid);
+    params->flags = cpu_to_le16(flag);
+    params->result = cpu_to_le16(result);
+    if (len)
+        memcpy(params->data, data, len);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static void l2cap_disconnection_response(struct l2cap_instance_s *l2cap,
+                int dcid, int scid)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    l2cap_disconn_rsp *params;
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + L2CAP_DISCONN_RSP_SIZE);
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    hdr->code = L2CAP_DISCONN_RSP;
+    hdr->ident = l2cap->last_id;
+    hdr->len = cpu_to_le16(L2CAP_DISCONN_RSP_SIZE);
+
+    params->dcid = cpu_to_le16(dcid);
+    params->scid = cpu_to_le16(scid);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static void l2cap_echo_response(struct l2cap_instance_s *l2cap,
+                const uint8_t *data, int len)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    uint8_t *params;
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + len);
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    hdr->code = L2CAP_ECHO_RSP;
+    hdr->ident = l2cap->last_id;
+    hdr->len = cpu_to_le16(len);
+
+    memcpy(params, data, len);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static void l2cap_info_response(struct l2cap_instance_s *l2cap, int type,
+                int result, const uint8_t *data, int len)
+{
+    uint8_t *pkt;
+    l2cap_cmd_hdr *hdr;
+    l2cap_info_rsp *params;
+
+    pkt = l2cap->signalling_ch.params.sdu_out(&l2cap->signalling_ch.params,
+                    L2CAP_CMD_HDR_SIZE + L2CAP_INFO_RSP_SIZE + len);
+    hdr = (void *) (pkt + 0);
+    params = (void *) (pkt + L2CAP_CMD_HDR_SIZE);
+
+    hdr->code = L2CAP_INFO_RSP;
+    hdr->ident = l2cap->last_id;
+    hdr->len = cpu_to_le16(L2CAP_INFO_RSP_SIZE + len);
+
+    params->type = cpu_to_le16(type);
+    params->result = cpu_to_le16(result);
+    if (len)
+       memcpy(params->data, data, len);
+
+    l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
+}
+
+static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, int len);
+static void l2cap_bframe_submit(struct bt_l2cap_conn_params_s *parms);
+#if 0
+static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, int len);
+static void l2cap_iframe_submit(struct bt_l2cap_conn_params_s *parm);
+#endif
+static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid,
+                const l2cap_hdr *hdr, int len);
+static void l2cap_iframe_in(struct l2cap_chan_s *ch, uint16_t cid,
+                const l2cap_hdr *hdr, int len);
+
+static int l2cap_cid_new(struct l2cap_instance_s *l2cap)
+{
+    int i;
+
+    for (i = L2CAP_CID_ALLOC; i < L2CAP_CID_MAX; i ++)
+        if (!l2cap->cid[i])
+            return i;
+
+    return L2CAP_CID_INVALID;
+}
+
+static inline struct bt_l2cap_psm_s *l2cap_psm(
+                struct bt_l2cap_device_s *device, int psm)
+{
+    struct bt_l2cap_psm_s *ret = device->first_psm;
+
+    while (ret && ret->psm != psm)
+        ret = ret->next;
+
+    return ret;
+}
+
+static struct l2cap_chan_s *l2cap_channel_open(struct l2cap_instance_s *l2cap,
+                int psm, int source_cid)
+{
+    struct l2cap_chan_s *ch = NULL;
+    struct bt_l2cap_psm_s *psm_info;
+    int result, status;
+    int cid = l2cap_cid_new(l2cap);
+
+    if (cid) {
+        /* See what the channel is to be used for.. */
+        psm_info = l2cap_psm(l2cap->dev, psm);
+
+        if (psm_info) {
+            /* Device supports this use-case.  */
+            ch = qemu_mallocz(sizeof(*ch));
+            ch->params.sdu_out = l2cap_bframe_out;
+            ch->params.sdu_submit = l2cap_bframe_submit;
+            ch->frame_in = l2cap_bframe_in;
+            ch->mps = 65536;
+            ch->min_mtu = MAX(48, psm_info->min_mtu);
+            ch->params.remote_mtu = MAX(672, ch->min_mtu);
+            ch->remote_cid = source_cid;
+            ch->mode = L2CAP_MODE_BASIC;
+            ch->l2cap = l2cap;
+
+            /* Does it feel like opening yet another channel though?  */
+            if (!psm_info->new_channel(l2cap->dev, &ch->params)) {
+                l2cap->cid[cid] = ch;
+
+                result = L2CAP_CR_SUCCESS;
+                status = L2CAP_CS_NO_INFO;
+            } else {
+                qemu_free(ch);
+
+                result = L2CAP_CR_NO_MEM;
+                status = L2CAP_CS_NO_INFO;
+            }
+        } else {
+            result = L2CAP_CR_BAD_PSM;
+            status = L2CAP_CS_NO_INFO;
+        }
+    } else {
+        result = L2CAP_CR_NO_MEM;
+        status = L2CAP_CS_NO_INFO;
+    }
+
+    l2cap_connection_response(l2cap, cid, source_cid, result, status);
+
+    return ch;
+}
+
+static void l2cap_channel_close(struct l2cap_instance_s *l2cap,
+                int cid, int source_cid)
+{
+    struct l2cap_chan_s *ch = NULL;
+
+    /* According to Volume 3, section 6.1.1, pg 1048 of BT Core V2.0, a
+     * connection in CLOSED state still responds with a L2CAP_DisconnectRsp
+     * message on an L2CAP_DisconnectReq event.  */
+    if (unlikely(cid < L2CAP_CID_ALLOC)) {
+        l2cap_command_reject_cid(l2cap, l2cap->last_id, L2CAP_REJ_CID_INVAL,
+                        cid, source_cid);
+        return;
+    }
+    if (likely(cid >= L2CAP_CID_ALLOC && cid < L2CAP_CID_MAX))
+        ch = l2cap->cid[cid];
+
+    if (likely(ch)) {
+        if (ch->remote_cid != source_cid) {
+            fprintf(stderr, "%s: Ignoring a Disconnection Request with the "
+                            "invalid SCID %04x.\n", __FUNCTION__, source_cid);
+            return;
+        }
+
+        l2cap->cid[cid] = NULL;
+
+        ch->params.close(ch->params.opaque);
+        qemu_free(ch);
+    }
+
+    l2cap_disconnection_response(l2cap, cid, source_cid);
+}
+
+static void l2cap_channel_config_null(struct l2cap_instance_s *l2cap,
+                struct l2cap_chan_s *ch)
+{
+    l2cap_configuration_request(l2cap, ch->remote_cid, 0, NULL, 0);
+    ch->config_req_id = l2cap->last_id;
+    ch->config &= ~L2CAP_CFG_INIT;
+}
+
+static void l2cap_channel_config_req_event(struct l2cap_instance_s *l2cap,
+                struct l2cap_chan_s *ch)
+{
+    /* Use all default channel options and terminate negotiation.  */
+    l2cap_channel_config_null(l2cap, ch);
+}
+
+static int l2cap_channel_config(struct l2cap_instance_s *l2cap,
+                struct l2cap_chan_s *ch, int flag,
+                const uint8_t *data, int len)
+{
+    l2cap_conf_opt *opt;
+    l2cap_conf_opt_qos *qos;
+    uint32_t val;
+    uint8_t rsp[len];
+    int result = L2CAP_CONF_SUCCESS;
+
+    data = memcpy(rsp, data, len);
+    while (len) {
+        opt = (void *) data;
+
+        if (len < L2CAP_CONF_OPT_SIZE ||
+                        len < L2CAP_CONF_OPT_SIZE + opt->len) {
+            result = L2CAP_CONF_REJECT;
+            break;
+        }
+        data += L2CAP_CONF_OPT_SIZE + opt->len;
+        len -= L2CAP_CONF_OPT_SIZE + opt->len;
+
+        switch (opt->type & 0x7f) {
+        case L2CAP_CONF_MTU:
+            if (opt->len != 2) {
+                result = L2CAP_CONF_REJECT;
+                break;
+            }
+
+            /* MTU */
+            val = le16_to_cpup((void *) opt->val);
+            if (val < ch->min_mtu) {
+                cpu_to_le16w((void *) opt->val, ch->min_mtu);
+                result = L2CAP_CONF_UNACCEPT;
+                break;
+            }
+
+            ch->params.remote_mtu = val;
+            break;
+
+        case L2CAP_CONF_FLUSH_TO:
+            if (opt->len != 2) {
+                result = L2CAP_CONF_REJECT;
+                break;
+            }
+
+            /* Flush Timeout */
+            val = le16_to_cpup((void *) opt->val);
+            if (val < 0x0001) {
+                opt->val[0] = 0xff;
+                opt->val[1] = 0xff;
+                result = L2CAP_CONF_UNACCEPT;
+                break;
+            }
+            break;
+
+        case L2CAP_CONF_QOS:
+            if (opt->len != L2CAP_CONF_OPT_QOS_SIZE) {
+                result = L2CAP_CONF_REJECT;
+                break;
+            }
+            qos = (void *) opt->val;
+
+            /* Flags */
+            val = qos->flags;
+            if (val) {
+                qos->flags = 0;
+                result = L2CAP_CONF_UNACCEPT;
+            }
+
+            /* Service type */
+            val = qos->service_type;
+            if (val != L2CAP_CONF_QOS_BEST_EFFORT &&
+                            val != L2CAP_CONF_QOS_NO_TRAFFIC) {
+                qos->service_type = L2CAP_CONF_QOS_BEST_EFFORT;
+                result = L2CAP_CONF_UNACCEPT;
+            }
+
+            if (val != L2CAP_CONF_QOS_NO_TRAFFIC) {
+                /* XXX: These values should possibly be calculated
+                 * based on LM / baseband properties also.  */
+
+                /* Token rate */
+                val = le32_to_cpu(qos->token_rate);
+                if (val == L2CAP_CONF_QOS_WILDCARD)
+                    qos->token_rate = cpu_to_le32(0x100000);
+
+                /* Token bucket size */
+                val = le32_to_cpu(qos->token_bucket_size);
+                if (val == L2CAP_CONF_QOS_WILDCARD)
+                    qos->token_bucket_size = cpu_to_le32(65500);
+
+                /* Any Peak bandwidth value is correct to return as-is */
+                /* Any Access latency value is correct to return as-is */
+                /* Any Delay variation value is correct to return as-is */
+            }
+            break;
+
+        case L2CAP_CONF_RFC:
+            if (opt->len != 9) {
+                result = L2CAP_CONF_REJECT;
+                break;
+            }
+
+            /* Mode */
+            val = opt->val[0];
+            switch (val) {
+            case L2CAP_MODE_BASIC:
+                ch->mode = val;
+                ch->frame_in = l2cap_bframe_in;
+
+                /* All other parameters shall be ignored */
+                break;
+
+            case L2CAP_MODE_RETRANS:
+            case L2CAP_MODE_FLOWCTL:
+                ch->mode = val;
+                ch->frame_in = l2cap_iframe_in;
+                /* Note: most of these parameters refer to incoming traffic
+                 * so we don't need to save them as long as we can accept
+                 * incoming PDUs at any values of the parameters.  */
+
+                /* TxWindow size */
+                val = opt->val[1];
+                if (val < 1 || val > 32) {
+                    opt->val[1] = 32;
+                    result = L2CAP_CONF_UNACCEPT;
+                    break;
+                }
+
+                /* MaxTransmit */
+                val = opt->val[2];
+                if (val < 1) {
+                    opt->val[2] = 1;
+                    result = L2CAP_CONF_UNACCEPT;
+                    break;
+                }
+
+                /* Remote Retransmission time-out shouldn't affect local
+                 * operation (?) */
+
+                /* The Monitor time-out drives the local Monitor timer (?),
+                 * so save the value.  */
+                val = (opt->val[6] << 8) | opt->val[5];
+                if (val < 30) {
+                    opt->val[5] = 100 & 0xff;
+                    opt->val[6] = 100 >> 8;
+                    result = L2CAP_CONF_UNACCEPT;
+                    break;
+                }
+                ch->monitor_timeout = val;
+                l2cap_monitor_timer_update(ch);
+
+                /* MPS */
+                val = (opt->val[8] << 8) | opt->val[7];
+                if (val < ch->min_mtu) {
+                    opt->val[7] = ch->min_mtu & 0xff;
+                    opt->val[8] = ch->min_mtu >> 8;
+                    result = L2CAP_CONF_UNACCEPT;
+                    break;
+                }
+                ch->mps = val;
+                break;
+
+            default:
+                result = L2CAP_CONF_UNACCEPT;
+                break;
+            }
+            break;
+
+        default:
+            if (!(opt->type >> 7))
+                result = L2CAP_CONF_UNKNOWN;
+            break;
+        }
+
+        if (result != L2CAP_CONF_SUCCESS)
+            break;	/* XXX: should continue? */
+    }
+
+    l2cap_configuration_response(l2cap, ch->remote_cid,
+                    flag, result, rsp, len);
+
+    return result == L2CAP_CONF_SUCCESS && !flag;
+}
+
+static void l2cap_channel_config_req_msg(struct l2cap_instance_s *l2cap,
+                int flag, int cid, const uint8_t *data, int len)
+{
+    struct l2cap_chan_s *ch;
+
+    if (unlikely(cid >= L2CAP_CID_MAX || !l2cap->cid[cid])) {
+        l2cap_command_reject_cid(l2cap, l2cap->last_id, L2CAP_REJ_CID_INVAL,
+                        cid, 0x0000);
+        return;
+    }
+    ch = l2cap->cid[cid];
+
+    /* From OPEN go to WAIT_CONFIG_REQ and from WAIT_CONFIG_REQ_RSP to
+     * WAIT_CONFIG_REQ_RSP.  This is assuming the transition chart for OPEN
+     * on pg 1053, section 6.1.5, volume 3 of BT Core V2.0 has a mistake
+     * and on options-acceptable we go back to OPEN and otherwise to
+     * WAIT_CONFIG_REQ and not the other way.  */
+    ch->config &= ~L2CAP_CFG_ACC;
+
+    if (l2cap_channel_config(l2cap, ch, flag, data, len))
+        /* Go to OPEN or WAIT_CONFIG_RSP */
+        ch->config |= L2CAP_CFG_ACC;
+
+    /* TODO: if the incoming traffic flow control or retransmission mode
+     * changed then we probably need to also generate the
+     * ConfigureChannel_Req event and set the outgoing traffic to the same
+     * mode.  */
+    if (!(ch->config & L2CAP_CFG_INIT) && (ch->config & L2CAP_CFG_ACC) &&
+                    !ch->config_req_id)
+        l2cap_channel_config_req_event(l2cap, ch);
+}
+
+static int l2cap_channel_config_rsp_msg(struct l2cap_instance_s *l2cap,
+                int result, int flag, int cid, const uint8_t *data, int len)
+{
+    struct l2cap_chan_s *ch;
+
+    if (unlikely(cid >= L2CAP_CID_MAX || !l2cap->cid[cid])) {
+        l2cap_command_reject_cid(l2cap, l2cap->last_id, L2CAP_REJ_CID_INVAL,
+                        cid, 0x0000);
+        return 0;
+    }
+    ch = l2cap->cid[cid];
+
+    if (ch->config_req_id != l2cap->last_id)
+        return 1;
+    ch->config_req_id = 0;
+
+    if (result == L2CAP_CONF_SUCCESS) {
+        if (!flag)
+            ch->config |= L2CAP_CFG_INIT;
+        else
+            l2cap_channel_config_null(l2cap, ch);
+    } else
+        /* Retry until we succeed */
+        l2cap_channel_config_req_event(l2cap, ch);
+
+    return 0;
+}
+
+static void l2cap_channel_open_req_msg(struct l2cap_instance_s *l2cap,
+                int psm, int source_cid)
+{
+    struct l2cap_chan_s *ch = l2cap_channel_open(l2cap, psm, source_cid);
+
+    if (!ch)
+        return;
+
+    /* Optional */
+    if (!(ch->config & L2CAP_CFG_INIT) && !ch->config_req_id)
+        l2cap_channel_config_req_event(l2cap, ch);
+}
+
+static void l2cap_info(struct l2cap_instance_s *l2cap, int type)
+{
+    uint8_t data[4];
+    int len = 0;
+    int result = L2CAP_IR_SUCCESS;
+
+    switch (type) {
+    case L2CAP_IT_CL_MTU:
+        data[len ++] = l2cap->group_ch.mps & 0xff;
+        data[len ++] = l2cap->group_ch.mps >> 8;
+        break;
+
+    case L2CAP_IT_FEAT_MASK:
+        /* (Prematurely) report Flow control and Retransmission modes.  */
+        data[len ++] = 0x03;
+        data[len ++] = 0x00;
+        data[len ++] = 0x00;
+        data[len ++] = 0x00;
+        break;
+
+    default:
+        result = L2CAP_IR_NOTSUPP;
+    }
+
+    l2cap_info_response(l2cap, type, result, data, len);
+}
+
+static void l2cap_command(struct l2cap_instance_s *l2cap, int code, int id,
+                const uint8_t *params, int len)
+{
+    int err;
+
+#if 0
+    /* TODO: do the IDs really have to be in sequence?  */
+    if (!id || (id != l2cap->last_id && id != l2cap->next_id)) {
+        fprintf(stderr, "%s: out of sequence command packet ignored.\n",
+                        __FUNCTION__);
+        return;
+    }
+#else
+    l2cap->next_id = id;
+#endif
+    if (id == l2cap->next_id) {
+        l2cap->last_id = l2cap->next_id;
+        l2cap->next_id = l2cap->next_id == 255 ? 1 : l2cap->next_id + 1;
+    } else {
+        /* TODO: Need to re-send the same response, without re-executing
+         * the corresponding command!  */
+    }
+
+    switch (code) {
+    case L2CAP_COMMAND_REJ:
+        if (unlikely(len != 2 && len != 4 && len != 6)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        /* We never issue commands other than Command Reject currently.  */
+        fprintf(stderr, "%s: stray Command Reject (%02x, %04x) "
+                        "packet, ignoring.\n", __FUNCTION__, id,
+                        le16_to_cpu(((l2cap_cmd_rej *) params)->reason));
+        break;
+
+    case L2CAP_CONN_REQ:
+        if (unlikely(len != L2CAP_CONN_REQ_SIZE)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        l2cap_channel_open_req_msg(l2cap,
+                        le16_to_cpu(((l2cap_conn_req *) params)->psm),
+                        le16_to_cpu(((l2cap_conn_req *) params)->scid));
+        break;
+
+    case L2CAP_CONN_RSP:
+        if (unlikely(len != L2CAP_CONN_RSP_SIZE)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        /* We never issue Connection Requests currently. TODO  */
+        fprintf(stderr, "%s: unexpected Connection Response (%02x) "
+                        "packet, ignoring.\n", __FUNCTION__, id);
+        break;
+
+    case L2CAP_CONF_REQ:
+        if (unlikely(len < L2CAP_CONF_REQ_SIZE(0))) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        l2cap_channel_config_req_msg(l2cap,
+                        le16_to_cpu(((l2cap_conf_req *) params)->flags) & 1,
+                        le16_to_cpu(((l2cap_conf_req *) params)->dcid),
+                        ((l2cap_conf_req *) params)->data,
+                        len - L2CAP_CONF_REQ_SIZE(0));
+        break;
+
+    case L2CAP_CONF_RSP:
+        if (unlikely(len < L2CAP_CONF_RSP_SIZE(0))) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        if (l2cap_channel_config_rsp_msg(l2cap,
+                        le16_to_cpu(((l2cap_conf_rsp *) params)->result),
+                        le16_to_cpu(((l2cap_conf_rsp *) params)->flags) & 1,
+                        le16_to_cpu(((l2cap_conf_rsp *) params)->scid),
+                        ((l2cap_conf_rsp *) params)->data,
+                        len - L2CAP_CONF_RSP_SIZE(0)))
+            fprintf(stderr, "%s: unexpected Configure Response (%02x) "
+                            "packet, ignoring.\n", __FUNCTION__, id);
+        break;
+
+    case L2CAP_DISCONN_REQ:
+        if (unlikely(len != L2CAP_DISCONN_REQ_SIZE)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        l2cap_channel_close(l2cap,
+                        le16_to_cpu(((l2cap_disconn_req *) params)->dcid),
+                        le16_to_cpu(((l2cap_disconn_req *) params)->scid));
+        break;
+
+    case L2CAP_DISCONN_RSP:
+        if (unlikely(len != L2CAP_DISCONN_RSP_SIZE)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        /* We never issue Disconnection Requests currently. TODO  */
+        fprintf(stderr, "%s: unexpected Disconnection Response (%02x) "
+                        "packet, ignoring.\n", __FUNCTION__, id);
+        break;
+
+    case L2CAP_ECHO_REQ:
+        l2cap_echo_response(l2cap, params, len);
+        break;
+
+    case L2CAP_ECHO_RSP:
+        /* We never issue Echo Requests currently. TODO  */
+        fprintf(stderr, "%s: unexpected Echo Response (%02x) "
+                        "packet, ignoring.\n", __FUNCTION__, id);
+        break;
+
+    case L2CAP_INFO_REQ:
+        if (unlikely(len != L2CAP_INFO_REQ_SIZE)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        l2cap_info(l2cap, le16_to_cpu(((l2cap_info_req *) params)->type));
+        break;
+
+    case L2CAP_INFO_RSP:
+        if (unlikely(len != L2CAP_INFO_RSP_SIZE)) {
+            err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+            goto reject;
+        }
+
+        /* We never issue Information Requests currently. TODO  */
+        fprintf(stderr, "%s: unexpected Information Response (%02x) "
+                        "packet, ignoring.\n", __FUNCTION__, id);
+        break;
+
+    default:
+        err = L2CAP_REJ_CMD_NOT_UNDERSTOOD;
+    reject:
+        l2cap_command_reject(l2cap, id, err, 0, 0);
+        break;
+    }
+}
+
+static void l2cap_rexmit_enable(struct l2cap_chan_s *ch, int enable)
+{
+    ch->rexmit = enable;
+
+    l2cap_retransmission_timer_update(ch);
+    l2cap_monitor_timer_update(ch);
+}
+
+/* Command frame SDU */
+static void l2cap_cframe_in(void *opaque, const uint8_t *data, int len)
+{
+    struct l2cap_instance_s *l2cap = opaque;
+    const l2cap_cmd_hdr *hdr;
+    int clen;
+
+    while (len) {
+        hdr = (void *) data;
+        if (len < L2CAP_CMD_HDR_SIZE)
+            /* TODO: signal an error */
+            return;
+        len -= L2CAP_CMD_HDR_SIZE;
+        data += L2CAP_CMD_HDR_SIZE;
+
+        clen = le16_to_cpu(hdr->len);
+        if (len < clen) {
+            l2cap_command_reject(l2cap, hdr->ident,
+                            L2CAP_REJ_CMD_NOT_UNDERSTOOD, 0, 0);
+            break;
+        }
+
+        l2cap_command(l2cap, hdr->code, hdr->ident, data, clen);
+        len -= clen;
+        data += clen;
+    }
+}
+
+/* Group frame SDU */
+static void l2cap_gframe_in(void *opaque, const uint8_t *data, int len)
+{
+}
+
+/* Supervisory frame */
+static void l2cap_sframe_in(struct l2cap_chan_s *ch, uint16_t ctrl)
+{
+}
+
+/* Basic L2CAP mode Information frame */
+static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid,
+                const l2cap_hdr *hdr, int len)
+{
+    /* We have a full SDU, no further processing */
+    ch->params.sdu_in(ch->params.opaque, hdr->data, len);
+}
+
+/* Flow Control and Retransmission mode frame */
+static void l2cap_iframe_in(struct l2cap_chan_s *ch, uint16_t cid,
+                const l2cap_hdr *hdr, int len)
+{
+    uint16_t fcs = le16_to_cpup((void *) (hdr->data + len - 2));
+
+    if (len < 4)
+        goto len_error;
+    if (l2cap_fcs16((const uint8_t *) hdr, L2CAP_HDR_SIZE + len - 2) != fcs)
+        goto fcs_error;
+
+    if ((hdr->data[0] >> 7) == ch->rexmit)
+        l2cap_rexmit_enable(ch, !(hdr->data[0] >> 7));
+
+    if (hdr->data[0] & 1) {
+        if (len != 4)
+            /* TODO: Signal an error? */;
+            return;
+
+        return l2cap_sframe_in(ch, le16_to_cpup((void *) hdr->data));
+    }
+
+    switch (hdr->data[1] >> 6) {	/* SAR */
+    case L2CAP_SAR_NO_SEG:
+        if (ch->len_total)
+            goto seg_error;
+        if (len - 4 > ch->mps)
+            goto len_error;
+
+        return ch->params.sdu_in(ch->params.opaque, hdr->data + 2, len - 4);
+
+    case L2CAP_SAR_START:
+        if (ch->len_total || len < 6)
+            goto seg_error;
+        if (len - 6 > ch->mps)
+            goto len_error;
+
+        ch->len_total = le16_to_cpup((void *) (hdr->data + 2));
+        if (len >= 6 + ch->len_total)
+            goto seg_error;
+
+        ch->len_cur = len - 6;
+        memcpy(ch->sdu, hdr->data + 4, ch->len_cur);
+        break;
+
+    case L2CAP_SAR_END:
+        if (!ch->len_total || ch->len_cur + len - 4 < ch->len_total)
+            goto seg_error;
+        if (len - 4 > ch->mps)
+            goto len_error;
+
+        memcpy(ch->sdu + ch->len_cur, hdr->data + 2, len - 4);
+        return ch->params.sdu_in(ch->params.opaque, ch->sdu, ch->len_total);
+
+    case L2CAP_SAR_CONT:
+        if (!ch->len_total || ch->len_cur + len - 4 >= ch->len_total)
+            goto seg_error;
+        if (len - 4 > ch->mps)
+            goto len_error;
+
+        memcpy(ch->sdu + ch->len_cur, hdr->data + 2, len - 4);
+        ch->len_cur += len - 4;
+        break;
+
+    seg_error:
+    len_error:	/* TODO */
+    fcs_error:	/* TODO */
+        ch->len_cur = 0;
+        ch->len_total = 0;
+        break;
+    }
+}
+
+static void l2cap_frame_in(struct l2cap_instance_s *l2cap,
+                const l2cap_hdr *frame)
+{
+    uint16_t cid = le16_to_cpu(frame->cid);
+    uint16_t len = le16_to_cpu(frame->len);
+
+    if (unlikely(cid >= L2CAP_CID_MAX || !l2cap->cid[cid])) {
+        fprintf(stderr, "%s: frame addressed to a non-existent L2CAP "
+                        "channel %04x received.\n", __FUNCTION__, cid);
+        return;
+    }
+
+    l2cap->cid[cid]->frame_in(l2cap->cid[cid], cid, frame, len);
+}
+
+/* "Recombination" */
+static void l2cap_pdu_in(struct l2cap_instance_s *l2cap,
+                const uint8_t *data, int len)
+{
+    const l2cap_hdr *hdr = (void *) l2cap->frame_in;
+
+    if (unlikely(len + l2cap->frame_in_len > sizeof(l2cap->frame_in))) {
+        if (l2cap->frame_in_len < sizeof(l2cap->frame_in)) {
+            memcpy(l2cap->frame_in + l2cap->frame_in_len, data,
+                            sizeof(l2cap->frame_in) - l2cap->frame_in_len);
+            l2cap->frame_in_len = sizeof(l2cap->frame_in);
+            /* TODO: truncate */
+            l2cap_frame_in(l2cap, hdr);
+        }
+
+        return;
+    }
+
+    memcpy(l2cap->frame_in + l2cap->frame_in_len, data, len);
+    l2cap->frame_in_len += len;
+
+    if (len >= L2CAP_HDR_SIZE)
+        if (len >= L2CAP_HDR_SIZE + le16_to_cpu(hdr->len))
+            l2cap_frame_in(l2cap, hdr);
+            /* There is never a start of a new PDU in the same ACL packet, so
+             * no need to memmove the remaining payload and loop.  */
+}
+
+static inline uint8_t *l2cap_pdu_out(struct l2cap_instance_s *l2cap,
+                uint16_t cid, uint16_t len)
+{
+    l2cap_hdr *hdr = (void *) l2cap->frame_out;
+
+    l2cap->frame_out_len = len + L2CAP_HDR_SIZE;
+
+    hdr->cid = cpu_to_le16(cid);
+    hdr->len = cpu_to_le16(len);
+
+    return l2cap->frame_out + L2CAP_HDR_SIZE;
+}
+
+static inline void l2cap_pdu_submit(struct l2cap_instance_s *l2cap)
+{
+    /* TODO: Fragmentation */
+    (l2cap->role ?
+     l2cap->link->slave->lmp_acl_data : l2cap->link->host->lmp_acl_resp)
+            (l2cap->link, l2cap->frame_out, 1, l2cap->frame_out_len);
+}
+
+static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, int len)
+{
+    struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parm;
+
+    if (len > chan->params.remote_mtu) {
+        fprintf(stderr, "%s: B-Frame for CID %04x longer than %i octets.\n",
+                        __FUNCTION__,
+                        chan->remote_cid, chan->params.remote_mtu);
+        exit(-1);
+    }
+
+    return l2cap_pdu_out(chan->l2cap, chan->remote_cid, len);
+}
+
+static void l2cap_bframe_submit(struct bt_l2cap_conn_params_s *parms)
+{
+    struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parms;
+
+    return l2cap_pdu_submit(chan->l2cap);
+}
+
+#if 0
+/* Stub: Only used if an emulated device requests outgoing flow control */
+static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, int len)
+{
+    struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parm;
+
+    if (len > chan->params.remote_mtu) {
+        /* TODO: slice into segments and queue each segment as a separate
+         * I-Frame in a FIFO of I-Frames, local to the CID.  */
+    } else {
+        /* TODO: add to the FIFO of I-Frames, local to the CID.  */
+        /* Possibly we need to return a pointer to a contiguous buffer
+         * for now and then memcpy from it into FIFOs in l2cap_iframe_submit
+         * while segmenting at the same time.  */
+    }
+    return 0;
+}
+
+static void l2cap_iframe_submit(struct bt_l2cap_conn_params_s *parm)
+{
+    /* TODO: If flow control indicates clear to send, start submitting the
+     * invidual I-Frames from the FIFO, but don't remove them from there.
+     * Kick the appropriate timer until we get an S-Frame, and only then
+     * remove from FIFO or resubmit and re-kick the timer if the timer
+     * expired.  */
+}
+#endif
+
+static void l2cap_init(struct l2cap_instance_s *l2cap,
+                struct bt_link_s *link, int role)
+{
+    l2cap->link = link;
+    l2cap->role = role;
+    l2cap->dev = (struct bt_l2cap_device_s *)
+            (role ? link->host : link->slave);
+
+    l2cap->next_id = 1;
+
+    /* Establish the signalling channel */
+    l2cap->signalling_ch.params.sdu_in = l2cap_cframe_in;
+    l2cap->signalling_ch.params.sdu_out = l2cap_bframe_out;
+    l2cap->signalling_ch.params.sdu_submit = l2cap_bframe_submit;
+    l2cap->signalling_ch.params.opaque = l2cap;
+    l2cap->signalling_ch.params.remote_mtu = 48;
+    l2cap->signalling_ch.remote_cid = L2CAP_CID_SIGNALLING;
+    l2cap->signalling_ch.frame_in = l2cap_bframe_in;
+    l2cap->signalling_ch.mps = 65536;
+    l2cap->signalling_ch.min_mtu = 48;
+    l2cap->signalling_ch.mode = L2CAP_MODE_BASIC;
+    l2cap->signalling_ch.l2cap = l2cap;
+    l2cap->cid[L2CAP_CID_SIGNALLING] = &l2cap->signalling_ch;
+
+    /* Establish the connection-less data channel */
+    l2cap->group_ch.params.sdu_in = l2cap_gframe_in;
+    l2cap->group_ch.params.opaque = l2cap;
+    l2cap->group_ch.frame_in = l2cap_bframe_in;
+    l2cap->group_ch.mps = 65533;
+    l2cap->group_ch.l2cap = l2cap;
+    l2cap->group_ch.remote_cid = L2CAP_CID_INVALID;
+    l2cap->cid[L2CAP_CID_GROUP] = &l2cap->group_ch;
+}
+
+static void l2cap_teardown(struct l2cap_instance_s *l2cap, int send_disconnect)
+{
+    int cid;
+
+    /* Don't send DISCONNECT if we are currently handling a DISCONNECT
+     * sent from the other side.  */
+    if (send_disconnect) {
+        if (l2cap->role)
+            l2cap->dev->device.lmp_disconnect_slave(l2cap->link);
+            /* l2cap->link is invalid from now on.  */
+        else
+            l2cap->dev->device.lmp_disconnect_master(l2cap->link);
+    }
+
+    for (cid = L2CAP_CID_ALLOC; cid < L2CAP_CID_MAX; cid ++)
+        if (l2cap->cid[cid]) {
+            l2cap->cid[cid]->params.close(l2cap->cid[cid]->params.opaque);
+            free(l2cap->cid[cid]);
+        }
+
+    if (l2cap->role)
+        qemu_free(l2cap);
+    else
+        qemu_free(l2cap->link);
+}
+
+/* L2CAP glue to lower layers in bluetooth stack (LMP) */
+
+static void l2cap_lmp_connection_request(struct bt_link_s *link)
+{
+    struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->slave;
+    struct slave_l2cap_instance_s *l2cap;
+
+    /* Always accept - we only get called if (dev->device->page_scan).  */
+
+    l2cap = qemu_mallocz(sizeof(struct slave_l2cap_instance_s));
+    l2cap->link.slave = &dev->device;
+    l2cap->link.host = link->host;
+    l2cap_init(&l2cap->l2cap, &l2cap->link, 0);
+
+    /* Always at the end */
+    link->host->reject_reason = 0;
+    link->host->lmp_connection_complete(&l2cap->link);
+}
+
+/* Stub */
+static void l2cap_lmp_connection_complete(struct bt_link_s *link)
+{
+    struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host;
+    struct l2cap_instance_s *l2cap;
+
+    if (dev->device.reject_reason) {
+        /* Signal to upper layer */
+        return;
+    }
+
+    l2cap = qemu_mallocz(sizeof(struct l2cap_instance_s));
+    l2cap_init(l2cap, link, 1);
+
+    link->acl_mode = acl_active;
+
+    /* Signal to upper layer */
+}
+
+/* Stub */
+static void l2cap_lmp_disconnect_host(struct bt_link_s *link)
+{
+    struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host;
+    struct l2cap_instance_s *l2cap =
+            /* TODO: Retrieve from upper layer */ (void *) dev;
+
+    /* Signal to upper layer */
+
+    l2cap_teardown(l2cap, 0);
+}
+
+static void l2cap_lmp_disconnect_slave(struct bt_link_s *link)
+{
+    struct slave_l2cap_instance_s *l2cap =
+            (struct slave_l2cap_instance_s *) link;
+
+    l2cap_teardown(&l2cap->l2cap, 0);
+}
+
+static void l2cap_lmp_acl_data_slave(struct bt_link_s *link,
+                const uint8_t *data, int start, int len)
+{
+    struct slave_l2cap_instance_s *l2cap =
+            (struct slave_l2cap_instance_s *) link;
+
+    if (start)
+        l2cap->l2cap.frame_in_len = 0;
+
+    l2cap_pdu_in(&l2cap->l2cap, data, len);
+}
+
+/* Stub */
+static void l2cap_lmp_acl_data_host(struct bt_link_s *link,
+                const uint8_t *data, int start, int len)
+{
+    struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host;
+    struct l2cap_instance_s *l2cap =
+            /* TODO: Retrieve from upper layer */ (void *) dev;
+
+    if (start)
+        l2cap->frame_in_len = 0;
+
+    l2cap_pdu_in(l2cap, data, len);
+}
+
+static void l2cap_dummy_destroy(struct bt_device_s *dev)
+{
+    struct bt_l2cap_device_s *l2cap_dev = (struct bt_l2cap_device_s *) dev;
+
+    bt_l2cap_device_done(l2cap_dev);
+}
+
+void bt_l2cap_device_init(struct bt_l2cap_device_s *dev,
+                struct bt_scatternet_s *net)
+{
+    bt_device_init(&dev->device, net);
+
+    dev->device.lmp_connection_request = l2cap_lmp_connection_request;
+    dev->device.lmp_connection_complete = l2cap_lmp_connection_complete;
+    dev->device.lmp_disconnect_master = l2cap_lmp_disconnect_host;
+    dev->device.lmp_disconnect_slave = l2cap_lmp_disconnect_slave;
+    dev->device.lmp_acl_data = l2cap_lmp_acl_data_slave;
+    dev->device.lmp_acl_resp = l2cap_lmp_acl_data_host;
+
+    dev->device.handle_destroy = l2cap_dummy_destroy;
+}
+
+void bt_l2cap_device_done(struct bt_l2cap_device_s *dev)
+{
+    bt_device_done(&dev->device);
+
+    /* Should keep a list of all instances and go through it and
+     * invoke l2cap_teardown() for each.  */
+}
+
+void bt_l2cap_psm_register(struct bt_l2cap_device_s *dev, int psm, int min_mtu,
+                int (*new_channel)(struct bt_l2cap_device_s *dev,
+                        struct bt_l2cap_conn_params_s *params))
+{
+    struct bt_l2cap_psm_s *new_psm = l2cap_psm(dev, psm);
+
+    if (new_psm) {
+        fprintf(stderr, "%s: PSM %04x already registered for device `%s'.\n",
+                        __FUNCTION__, psm, dev->device.lmp_name);
+        exit(-1);
+    }
+
+    new_psm = qemu_mallocz(sizeof(*new_psm));
+    new_psm->psm = psm;
+    new_psm->min_mtu = min_mtu;
+    new_psm->new_channel = new_channel;
+    new_psm->next = dev->first_psm;
+    dev->first_psm = new_psm;
+}