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Bluetooth: Add basic LE L2CAP connect request receiving support
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This patch adds the necessary boiler plate code to handle receiving
L2CAP connect requests over LE and respond to them with a proper connect
response.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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Johan Hedberg authored and holtmann committed Dec 5, 2013
1 parent 791d60f commit 27e2d4c
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Showing 2 changed files with 153 additions and 0 deletions.
1 change: 1 addition & 0 deletions include/net/bluetooth/l2cap.h
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Original file line number Diff line number Diff line change
Expand Up @@ -846,6 +846,7 @@ int l2cap_init_sockets(void);
void l2cap_cleanup_sockets(void);
bool l2cap_is_socket(struct socket *sock);

void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan);
void __l2cap_connect_rsp_defer(struct l2cap_chan *chan);

int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm);
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152 changes: 152 additions & 0 deletions net/bluetooth/l2cap_core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -617,6 +617,29 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
return;
}

static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
{
struct l2cap_conn *conn = chan->conn;
struct l2cap_le_conn_rsp rsp;
u16 result;

if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
result = L2CAP_CR_AUTHORIZATION;
else
result = L2CAP_CR_BAD_PSM;

l2cap_state_change(chan, BT_DISCONN);

rsp.dcid = cpu_to_le16(chan->scid);
rsp.mtu = cpu_to_le16(chan->imtu);
rsp.mps = __constant_cpu_to_le16(L2CAP_LE_DEFAULT_MPS);
rsp.credits = __constant_cpu_to_le16(L2CAP_LE_MAX_CREDITS);
rsp.result = cpu_to_le16(result);

l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
&rsp);
}

static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
{
struct l2cap_conn *conn = chan->conn;
Expand Down Expand Up @@ -663,6 +686,8 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason)
if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
if (conn->hcon->type == ACL_LINK)
l2cap_chan_connect_reject(chan);
else if (conn->hcon->type == LE_LINK)
l2cap_chan_le_connect_reject(chan);
}

l2cap_chan_del(chan, reason);
Expand Down Expand Up @@ -3641,6 +3666,23 @@ static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
return ptr - data;
}

void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
{
struct l2cap_le_conn_rsp rsp;
struct l2cap_conn *conn = chan->conn;

BT_DBG("chan %p", chan);

rsp.dcid = cpu_to_le16(chan->scid);
rsp.mtu = cpu_to_le16(chan->imtu);
rsp.mps = __constant_cpu_to_le16(L2CAP_LE_DEFAULT_MPS);
rsp.credits = __constant_cpu_to_le16(L2CAP_LE_MAX_CREDITS);
rsp.result = __constant_cpu_to_le16(L2CAP_CR_SUCCESS);

l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
&rsp);
}

void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
{
struct l2cap_conn_rsp rsp;
Expand Down Expand Up @@ -5382,6 +5424,113 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
return err;
}

static int l2cap_le_connect_req(struct l2cap_conn *conn,
struct l2cap_cmd_hdr *cmd, u16 cmd_len,
u8 *data)
{
struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
struct l2cap_le_conn_rsp rsp;
struct l2cap_chan *chan, *pchan;
u16 dcid, scid, mtu, mps;
__le16 psm;
u8 result;

if (cmd_len != sizeof(*req))
return -EPROTO;

scid = __le16_to_cpu(req->scid);
mtu = __le16_to_cpu(req->mtu);
mps = __le16_to_cpu(req->mps);
psm = req->psm;
dcid = 0;

if (mtu < 23 || mps < 23)
return -EPROTO;

BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
scid, mtu, mps);

/* Check if we have socket listening on psm */
pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
&conn->hcon->dst, LE_LINK);
if (!pchan) {
result = L2CAP_CR_BAD_PSM;
chan = NULL;
goto response;
}

mutex_lock(&conn->chan_lock);
l2cap_chan_lock(pchan);

if (!smp_sufficient_security(conn->hcon, pchan->sec_level)) {
result = L2CAP_CR_AUTHENTICATION;
chan = NULL;
goto response_unlock;
}

/* Check if we already have channel with that dcid */
if (__l2cap_get_chan_by_dcid(conn, scid)) {
result = L2CAP_CR_NO_MEM;
chan = NULL;
goto response_unlock;
}

chan = pchan->ops->new_connection(pchan);
if (!chan) {
result = L2CAP_CR_NO_MEM;
goto response_unlock;
}

bacpy(&chan->src, &conn->hcon->src);
bacpy(&chan->dst, &conn->hcon->dst);
chan->src_type = bdaddr_type(conn->hcon, conn->hcon->src_type);
chan->dst_type = bdaddr_type(conn->hcon, conn->hcon->dst_type);
chan->psm = psm;
chan->dcid = scid;
chan->omtu = mtu;
chan->remote_mps = mps;

__l2cap_chan_add(conn, chan);
dcid = chan->scid;

__set_chan_timer(chan, chan->ops->get_sndtimeo(chan));

chan->ident = cmd->ident;

if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
l2cap_state_change(chan, BT_CONNECT2);
result = L2CAP_CR_PEND;
chan->ops->defer(chan);
} else {
l2cap_chan_ready(chan);
result = L2CAP_CR_SUCCESS;
}

response_unlock:
l2cap_chan_unlock(pchan);
mutex_unlock(&conn->chan_lock);

if (result == L2CAP_CR_PEND)
return 0;

response:
if (chan) {
rsp.mtu = cpu_to_le16(chan->imtu);
rsp.mps = __constant_cpu_to_le16(L2CAP_LE_DEFAULT_MPS);
} else {
rsp.mtu = 0;
rsp.mps = 0;
}

rsp.dcid = cpu_to_le16(dcid);
rsp.credits = __constant_cpu_to_le16(L2CAP_LE_MAX_CREDITS);
rsp.result = cpu_to_le16(result);

l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);

return 0;
}

static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
struct l2cap_cmd_hdr *cmd, u16 cmd_len,
u8 *data)
Expand All @@ -5400,6 +5549,9 @@ static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
return 0;

case L2CAP_LE_CONN_REQ:
return l2cap_le_connect_req(conn, cmd, cmd_len, data);

default:
BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
return -EINVAL;
Expand Down

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