From bed68bde7ebdb591cc67921261307626c8f37936 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Thu, 17 May 2012 20:53:44 -0700 Subject: [PATCH] Bluetooth: Send SREJ frames when packets go missing The ERTM specification lays out three scenarios for sending SREJ frames to request retransmission of specific frames. l2cap_send_srej requests all frames up to a given txseq that are not already queued for reassembly. l2cap_send_srej_tail only requests the most recent missing frame. l2cap_send_srej_list resends SREJ frames for data that was requested for resend but never received. Signed-off-by: Mat Martineau Signed-off-by: Gustavo Padovan --- net/bluetooth/l2cap_core.c | 56 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 53 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 26963a5e3f58..5823697cf9de 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2239,17 +2239,67 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq) { - /* Placeholder */ + struct l2cap_ctrl control; + u16 seq; + + BT_DBG("chan %p, txseq %d", chan, txseq); + + memset(&control, 0, sizeof(control)); + control.sframe = 1; + control.super = L2CAP_SUPER_SREJ; + + for (seq = chan->expected_tx_seq; seq != txseq; + seq = __next_seq(chan, seq)) { + if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) { + control.reqseq = seq; + l2cap_send_sframe(chan, &control); + l2cap_seq_list_append(&chan->srej_list, seq); + } + } + + chan->expected_tx_seq = __next_seq(chan, txseq); } static void l2cap_send_srej_tail(struct l2cap_chan *chan) { - /* Placeholder */ + struct l2cap_ctrl control; + + BT_DBG("chan %p", chan); + + if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR) + return; + + memset(&control, 0, sizeof(control)); + control.sframe = 1; + control.super = L2CAP_SUPER_SREJ; + control.reqseq = chan->srej_list.tail; + l2cap_send_sframe(chan, &control); } static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq) { - /* Placeholder */ + struct l2cap_ctrl control; + u16 initial_head; + u16 seq; + + BT_DBG("chan %p, txseq %d", chan, txseq); + + memset(&control, 0, sizeof(control)); + control.sframe = 1; + control.super = L2CAP_SUPER_SREJ; + + /* Capture initial list head to allow only one pass through the list. */ + initial_head = chan->srej_list.head; + + do { + seq = l2cap_seq_list_pop(&chan->srej_list); + if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR) + break; + + control.reqseq = seq; + l2cap_send_sframe(chan, &control); + l2cap_seq_list_append(&chan->srej_list, seq); + } while (chan->srej_list.head != initial_head); } static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq) -- 2.20.1