From 3916aed81f1fd07f71a597080690d36f02e88850 Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Mon, 7 Oct 2013 15:35:26 +0200 Subject: [PATCH] Bluetooth: Limit LE MPS to the MTU value It doesn't make sense to have an MPS value greater than the configured MTU value since we will then not be able to fill up the packets to their full possible size. We need to set the MPS both in flowctl_init() as well as flowctl_start() since the imtu may change after init() but start() is only called after we've sent the LE Connection Request PDU which depends on having a valid MPS value. Signed-off-by: Johan Hedberg Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap_core.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 82aa6f352b20..4c8bac9e8d35 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -497,6 +497,11 @@ void l2cap_le_flowctl_init(struct l2cap_chan *chan) chan->mode = L2CAP_MODE_LE_FLOWCTL; chan->tx_credits = 0; chan->rx_credits = L2CAP_LE_MAX_CREDITS; + + if (chan->imtu < L2CAP_LE_DEFAULT_MPS) + chan->mps = chan->imtu; + else + chan->mps = L2CAP_LE_DEFAULT_MPS; } void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan) @@ -645,7 +650,7 @@ static void l2cap_chan_le_connect_reject(struct l2cap_chan *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.mps = cpu_to_le16(chan->mps); rsp.credits = cpu_to_le16(chan->rx_credits); rsp.result = cpu_to_le16(result); @@ -1201,6 +1206,11 @@ static void l2cap_le_flowctl_start(struct l2cap_chan *chan) chan->sdu_last_frag = NULL; chan->sdu_len = 0; + if (chan->imtu < L2CAP_LE_DEFAULT_MPS) + chan->mps = chan->imtu; + else + chan->mps = L2CAP_LE_DEFAULT_MPS; + skb_queue_head_init(&chan->tx_q); if (!chan->tx_credits) @@ -1232,7 +1242,7 @@ static void l2cap_le_connect(struct l2cap_chan *chan) req.psm = chan->psm; req.scid = cpu_to_le16(chan->scid); req.mtu = cpu_to_le16(chan->imtu); - req.mps = __constant_cpu_to_le16(L2CAP_LE_DEFAULT_MPS); + req.mps = cpu_to_le16(chan->mps); req.credits = cpu_to_le16(chan->rx_credits); chan->ident = l2cap_get_ident(conn); @@ -3826,7 +3836,7 @@ void __l2cap_le_connect_rsp_defer(struct l2cap_chan *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.mps = cpu_to_le16(chan->mps); rsp.credits = cpu_to_le16(chan->rx_credits); rsp.result = __constant_cpu_to_le16(L2CAP_CR_SUCCESS); @@ -5671,7 +5681,7 @@ response_unlock: response: if (chan) { rsp.mtu = cpu_to_le16(chan->imtu); - rsp.mps = __constant_cpu_to_le16(L2CAP_LE_DEFAULT_MPS); + rsp.mps = cpu_to_le16(chan->mps); } else { rsp.mtu = 0; rsp.mps = 0; -- 2.39.5