2010-06-01 06:54:17

by Suraj Sumangala

[permalink] [raw]
Subject: [PATCH 3/3] frame reassembly implementation for data from stream

Implemented hci_recv_stream_fragment to reassemble HCI packets received from any data stream
with packet type not known.

Signed-off-by: suraj <[email protected]>
---
include/net/bluetooth/hci_core.h | 1 +
net/bluetooth/hci_core.c | 104 ++++++++++++++++++++++++++++++++++++++
2 files changed, 105 insertions(+), 0 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 65c3c13..9892c26 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -429,6 +429,7 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb);
int hci_recv_frame(struct sk_buff *skb);
int hci_recv_packet_fragment(struct hci_dev *hdev, int type, void *data,
int count);
+int hci_recv_stream_fragment(struct hci_dev *hdev, void *data, int count);

int hci_register_sysfs(struct hci_dev *hdev);
void hci_unregister_sysfs(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index e7ce432..1587dc8 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1033,6 +1033,110 @@ EXPORT_SYMBOL(hci_recv_frame);
/* Receive packet type fragment */
#define __reassembly(hdev, type) ((hdev)->reassembly[(type) - 2])

+#define __get_max_rx_size(type) \
+ (((type) == HCI_ACLDATA_PKT) ? \
+ HCI_MAX_FRAME_SIZE : \
+ ((type) == HCI_EVENT_PKT) ? HCI_MAX_EVENT_SIZE :\
+ HCI_MAX_SCO_SIZE)
+
+#define __get_header_len(type) \
+ (((type) == HCI_ACLDATA_PKT) ? \
+ HCI_ACL_HDR_SIZE : \
+ ((type) == HCI_EVENT_PKT) ? HCI_EVENT_HDR_SIZE :\
+ HCI_SCO_HDR_SIZE)
+
+/* Receive fragment from data streams */
+int hci_recv_stream_fragment(struct hci_dev *hdev, void *data, int count)
+{
+ int type;
+
+ while (count) {
+ /*
+ * Reuse first pointer from reassembly array
+ */
+ struct sk_buff *skb = __reassembly(hdev, HCI_ACLDATA_PKT);
+
+ struct { int expect; int pkt_type; } *scb;
+ int len = 0;
+
+ if (!skb) {
+ struct { char type; } *pkt;
+
+ /* Start of the frame */
+ pkt = data;
+ type = pkt->type;
+
+ if (type < HCI_ACLDATA_PKT || type > HCI_EVENT_PKT)
+ return -EILSEQ;
+
+ len = __get_max_rx_size(type);
+
+ skb = bt_skb_alloc(len, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ scb = (void *) skb->cb;
+ scb->expect = __get_header_len(type);
+ scb->pkt_type = type;
+
+ skb->dev = (void *) hdev;
+ __reassembly(hdev, HCI_ACLDATA_PKT) = skb;
+
+ data++;
+ count--;
+
+ continue;
+ } else {
+ /* Continue of frame */
+ scb = (void *) skb->cb;
+ len = min(scb->expect, count);
+ type = scb->pkt_type;
+
+ memcpy(skb_put(skb, len), data, len);
+
+ count -= len;
+ data += len;
+ scb->expect -= len;
+ }
+
+ switch (type) {
+ case HCI_EVENT_PKT:
+ if (skb->len == HCI_EVENT_HDR_SIZE) {
+ struct hci_event_hdr *h = hci_event_hdr(skb);
+ scb->expect = h->plen;
+ }
+ break;
+
+ case HCI_ACLDATA_PKT:
+ if (skb->len == HCI_ACL_HDR_SIZE) {
+ struct hci_acl_hdr *h = hci_acl_hdr(skb);
+ scb->expect = __le16_to_cpu(h->dlen);
+ }
+ break;
+
+ case HCI_SCODATA_PKT:
+ if (skb->len == HCI_SCO_HDR_SIZE) {
+ struct hci_sco_hdr *h = hci_sco_hdr(skb);
+ scb->expect = h->dlen;
+ }
+ break;
+ }
+
+ if (scb->expect == 0) {
+ /* Complete frame */
+
+ __reassembly(hdev, HCI_ACLDATA_PKT) = NULL;
+
+ bt_cb(skb)->pkt_type = type;
+ hci_recv_frame(skb);
+ }
+
+ }
+ return 0;
+}
+EXPORT_SYMBOL(hci_recv_stream_fragment);
+
+/* Receive packet fragment with known packet type */
int hci_recv_packet_fragment(struct hci_dev *hdev, int type, void *data,
int count)
{
--
1.7.0