Return-Path: From: Johan Hedberg To: linux-bluetooth@vger.kernel.org Subject: [PATCH 23/31] Bluetooth: Add LE L2CAP segmentation support for outgoing data Date: Wed, 4 Dec 2013 16:11:19 +0200 Message-Id: <1386166287-13693-24-git-send-email-johan.hedberg@gmail.com> In-Reply-To: <1386166287-13693-1-git-send-email-johan.hedberg@gmail.com> References: <1386166287-13693-1-git-send-email-johan.hedberg@gmail.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: From: Johan Hedberg This patch adds segmentation support for outgoing data packets. Packets are segmented based on the MTU and MPS values. The l2cap_chan struct already contains many helpful variables from BR/EDR Enhanced L2CAP which can be used for this. Signed-off-by: Johan Hedberg --- net/bluetooth/l2cap_core.c | 127 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 126 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index b0287f57d534..2c591afccb51 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -607,6 +607,7 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err) break; case L2CAP_MODE_LE_FLOWCTL: + skb_queue_purge(&chan->tx_q); break; case L2CAP_MODE_ERTM: @@ -1194,12 +1195,24 @@ static void l2cap_move_done(struct l2cap_chan *chan) } } +static void l2cap_le_flowctl_start(struct l2cap_chan *chan) +{ + chan->sdu = NULL; + chan->sdu_last_frag = NULL; + chan->sdu_len = 0; + + skb_queue_head_init(&chan->tx_q); +} + static void l2cap_chan_ready(struct l2cap_chan *chan) { /* This clears all conf flags, including CONF_NOT_COMPLETE */ chan->conf_state = 0; __clear_chan_timer(chan); + if (chan->mode == L2CAP_MODE_LE_FLOWCTL) + l2cap_le_flowctl_start(chan); + chan->state = BT_CONNECTED; chan->ops->ready(chan); @@ -2521,6 +2534,89 @@ static int l2cap_segment_sdu(struct l2cap_chan *chan, return 0; } +static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan, + struct msghdr *msg, + size_t len, u16 sdulen) +{ + struct l2cap_conn *conn = chan->conn; + struct sk_buff *skb; + int err, count, hlen; + struct l2cap_hdr *lh; + + BT_DBG("chan %p len %zu", chan, len); + + if (!conn) + return ERR_PTR(-ENOTCONN); + + hlen = L2CAP_HDR_SIZE; + + if (sdulen) + hlen += L2CAP_SDULEN_SIZE; + + count = min_t(unsigned int, (conn->mtu - hlen), len); + + skb = chan->ops->alloc_skb(chan, count + hlen, + msg->msg_flags & MSG_DONTWAIT); + if (IS_ERR(skb)) + return skb; + + /* Create L2CAP header */ + lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE); + lh->cid = cpu_to_le16(chan->dcid); + lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE)); + + if (sdulen) + put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE)); + + err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb); + if (unlikely(err < 0)) { + kfree_skb(skb); + return ERR_PTR(err); + } + + return skb; +} + +static int l2cap_segment_le_sdu(struct l2cap_chan *chan, + struct sk_buff_head *seg_queue, + struct msghdr *msg, size_t len) +{ + struct sk_buff *skb; + size_t pdu_len; + u16 sdu_len; + + BT_DBG("chan %p, msg %p, len %zu", chan, msg, len); + + pdu_len = chan->conn->mtu - L2CAP_HDR_SIZE; + + pdu_len = min_t(size_t, pdu_len, chan->remote_mps); + + sdu_len = len; + pdu_len -= L2CAP_SDULEN_SIZE; + + while (len > 0) { + if (len <= pdu_len) + pdu_len = len; + + skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len); + if (IS_ERR(skb)) { + __skb_queue_purge(seg_queue); + return PTR_ERR(skb); + } + + __skb_queue_tail(seg_queue, skb); + + len -= pdu_len; + + if (sdu_len) { + sdu_len = 0; + pdu_len += L2CAP_SDULEN_SIZE; + } + } + + return 0; +} + int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, u32 priority) { @@ -2543,10 +2639,39 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, switch (chan->mode) { case L2CAP_MODE_LE_FLOWCTL: + /* Check outgoing MTU */ + if (len > chan->omtu) + return -EMSGSIZE; + if (!chan->tx_credits) return -EAGAIN; - /* fall through */ + __skb_queue_head_init(&seg_queue); + + err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len); + + if (chan->state != BT_CONNECTED) { + __skb_queue_purge(&seg_queue); + err = -ENOTCONN; + } + + if (err) + return err; + + skb_queue_splice_tail_init(&seg_queue, &chan->tx_q); + + while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) { + l2cap_do_send(chan, skb_dequeue(&chan->tx_q)); + chan->tx_credits--; + } + + if (!chan->tx_credits) + chan->ops->suspend(chan); + + err = len; + + break; + case L2CAP_MODE_BASIC: /* Check outgoing MTU */ if (len > chan->omtu) -- 1.8.4.2