Bluetooth: Fix/implement Three-wire reliable packet sending

This patch should complete the necessary code for sending reliable
Three-wire packets.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index f50afb2fb3646972f55a39a74231a0ebc6a355b6..6c7b27e921a53c03444f71699c9231bf12b6a4b7 100644 (file)
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -64,15 +64,15 @@ struct h5 {
        struct sk_buff          *rx_skb;        /* Receive buffer */
        size_t                  rx_pending;     /* Expecting more bytes */
        bool                    rx_esc;         /* SLIP escape mode */
+       u8                      rx_ack;         /* Last ack number received */
+       u8                      rx_seq;         /* Last seq number received */
 
        int                     (*rx_func) (struct hci_uart *hu, u8 c);
 
        struct timer_list       timer;          /* Retransmission timer */
 
-       bool                    txack_req;
-
-       u8                      next_ack;
-       u8                      next_seq;
+       bool                    tx_ack_req;     /* Pending ack to send */
+       u8                      tx_seq;         /* Next seq number to send */
 };
 
 static void h5_reset_rx(struct h5 *h5);
@@ -89,7 +89,7 @@ static void h5_timed_event(unsigned long arg)
        spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
 
        while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
-               h5->next_seq = (h5->next_seq - 1) & 0x07;
+               h5->tx_seq = (h5->tx_seq - 1) & 0x07;
                skb_queue_head(&h5->rel, skb);
        }
 
@@ -138,6 +138,45 @@ static int h5_close(struct hci_uart *hu)
        return 0;
 }
 
+static void h5_pkt_cull(struct h5 *h5)
+{
+       struct sk_buff *skb, *tmp;
+       unsigned long flags;
+       int i, to_remove;
+       u8 seq;
+
+       spin_lock_irqsave(&h5->unack.lock, flags);
+
+       to_remove = skb_queue_len(&h5->unack);
+
+       seq = h5->tx_seq;
+
+       while (to_remove > 0) {
+               if (h5->rx_ack == seq)
+                       break;
+
+               to_remove--;
+               seq = (seq - 1) % 8;
+       }
+
+       if (seq != h5->rx_ack)
+               BT_ERR("Controller acked invalid packet");
+
+       i = 0;
+       skb_queue_walk_safe(&h5->unack, skb, tmp) {
+               if (i++ >= to_remove)
+                       break;
+
+               __skb_unlink(skb, &h5->unack);
+               kfree_skb(skb);
+       }
+
+       if (skb_queue_empty(&h5->unack))
+               del_timer(&h5->timer);
+
+       spin_unlock_irqrestore(&h5->unack.lock, flags);
+}
+
 static void h5_handle_internal_rx(struct hci_uart *hu)
 {
        BT_DBG("%s", hu->hdev->name);
@@ -146,17 +185,24 @@ static void h5_handle_internal_rx(struct hci_uart *hu)
 static void h5_complete_rx_pkt(struct hci_uart *hu)
 {
        struct h5 *h5 = hu->priv;
-       u8 pkt_type;
+       const unsigned char *hdr = h5->rx_skb->data;
 
        BT_DBG("%s", hu->hdev->name);
 
-       pkt_type = h5->rx_skb->data[1] & 0x0f;
+       if (H5_HDR_RELIABLE(hdr)) {
+               h5->tx_seq = (h5->tx_seq + 1) % 8;
+               h5->tx_ack_req = true;
+       }
 
-       switch (pkt_type) {
+       h5->rx_ack = H5_HDR_ACK(hdr);
+
+       h5_pkt_cull(h5);
+
+       switch (H5_HDR_PKT_TYPE(hdr)) {
        case HCI_EVENT_PKT:
        case HCI_ACLDATA_PKT:
        case HCI_SCODATA_PKT:
-               bt_cb(h5->rx_skb)->pkt_type = pkt_type;
+               bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);
 
                /* Remove Three-wire header */
                skb_pull(h5->rx_skb, 4);
@@ -193,7 +239,7 @@ static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
 
        BT_DBG("%s 0x%02hhx", hu->hdev->name, c);
 
-       if ((hdr[0] >> 4) & 0x01) {
+       if (H5_HDR_CRC(hdr)) {
                h5->rx_func = h5_rx_crc;
                h5->rx_pending = 2;
        } else {
@@ -217,8 +263,15 @@ static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
                return 0;
        }
 
+       if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_seq) {
+               BT_ERR("Out-of-order packet arrived (%u != %u)",
+                      H5_HDR_SEQ(hdr), h5->tx_seq);
+               h5_reset_rx(h5);
+               return 0;
+       }
+
        h5->rx_func = h5_rx_payload;
-       h5->rx_pending = ((hdr[1] >> 4) & 0xff) + (hdr[2] << 4);
+       h5->rx_pending = H5_HDR_LEN(hdr);
 
        return 0;
 }
@@ -412,13 +465,13 @@ static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type,
 
        h5_slip_delim(nskb);
 
-       hdr[0] = h5->next_ack << 3;
-       h5->txack_req = false;
+       hdr[0] = h5->rx_seq << 3;
+       h5->tx_ack_req = false;
 
        if (rel) {
                hdr[0] |= 1 << 7;
-               hdr[0] |= h5->next_seq;
-               h5->next_seq = (h5->next_seq + 1) % 8;
+               hdr[0] |= h5->tx_seq;
+               h5->tx_seq = (h5->tx_seq + 1) % 8;
        }
 
        hdr[1] = pkt_type | ((len & 0x0f) << 4);
@@ -461,7 +514,7 @@ static struct sk_buff *h5_prepare_pkt(struct h5 *h5, u8 pkt_type,
 
 static struct sk_buff *h5_prepare_ack(struct h5 *h5)
 {
-       h5->txack_req = false;
+       h5->tx_ack_req = false;
        return NULL;
 }
 
@@ -505,7 +558,7 @@ static struct sk_buff *h5_dequeue(struct hci_uart *hu)
 unlock:
        spin_unlock_irqrestore(&h5->unack.lock, flags);
 
-       if (h5->txack_req)
+       if (h5->tx_ack_req)
                return h5_prepare_ack(h5);
 
        return NULL;