Implements feature to reassemble HCI frames received from an input stream.
Signed-off-by: Suraj Sumangala <[email protected]>
---
net/bluetooth/hci_core.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 106 insertions(+), 0 deletions(-)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index aeb2982..e1ede0b 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1033,6 +1033,112 @@ int hci_recv_frame(struct sk_buff *skb)
}
EXPORT_SYMBOL(hci_recv_frame);
+static int hci_reassembly(struct hci_dev *hdev, int type, void *data,
+ int count, struct sk_buff **skb_ptr, gfp_t how)
+{
+ int len = 0;
+ int header_len = 0;
+ int remain = count;
+ struct sk_buff *skb = *skb_ptr;
+ struct { struct bt_skb_cb cb_info; int expect; } *scb;
+
+ if (type < HCI_ACLDATA_PKT || type > HCI_EVENT_PKT)
+ return -EILSEQ;
+
+ if (!skb) {
+ switch (type) {
+ case HCI_ACLDATA_PKT:
+ len = HCI_MAX_FRAME_SIZE;
+ header_len = HCI_ACL_HDR_SIZE;
+ break;
+ case HCI_EVENT_PKT:
+ len = HCI_MAX_EVENT_SIZE;
+ header_len = HCI_EVENT_HDR_SIZE;
+ break;
+ case HCI_SCODATA_PKT:
+ len = HCI_MAX_SCO_SIZE;
+ header_len = HCI_SCO_HDR_SIZE;
+ break;
+ }
+
+ skb = bt_skb_alloc(len, how);
+ if (!skb)
+ return -ENOMEM;
+
+ scb = (void *) skb->cb;
+ scb->expect = header_len;
+ scb->cb_info.pkt_type = type;
+
+ skb->dev = (void *) hdev;
+ *skb_ptr = skb;
+ }
+
+ while (count) {
+ scb = (void *) skb->cb;
+ len = min(scb->expect, count);
+
+ memcpy(skb_put(skb, len), data, len);
+
+ count -= len;
+ data += len;
+ scb->expect -= len;
+ remain = count;
+
+ 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;
+
+ if (skb_tailroom(skb) < scb->expect) {
+ kfree_skb(skb);
+ *skb_ptr = NULL;
+ return -ENOMEM;
+ }
+ }
+ 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);
+
+ if (skb_tailroom(skb) < scb->expect) {
+ kfree_skb(skb);
+ *skb_ptr = NULL;
+ return -ENOMEM;
+ }
+ }
+ 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;
+
+ if (skb_tailroom(skb) < scb->expect) {
+ kfree_skb(skb);
+ *skb_ptr = NULL;
+ return -ENOMEM;
+ }
+ }
+ break;
+ }
+
+ if (scb->expect == 0) {
+ /* Complete frame */
+
+ bt_cb(skb)->pkt_type = type;
+ hci_recv_frame(skb);
+
+ *skb_ptr = NULL;
+ return remain;
+ }
+ }
+
+ return remain;
+}
+
/* Receive packet type fragment */
#define __reassembly(hdev, type) ((hdev)->reassembly[(type) - 2])
--
1.7.0.4
Hi Suraj,
> Implements feature to reassemble HCI frames received from an input stream.
>
> Signed-off-by: Suraj Sumangala <[email protected]>
> ---
> net/bluetooth/hci_core.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 106 insertions(+), 0 deletions(-)
>
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index aeb2982..e1ede0b 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -1033,6 +1033,112 @@ int hci_recv_frame(struct sk_buff *skb)
> }
> EXPORT_SYMBOL(hci_recv_frame);
>
> +static int hci_reassembly(struct hci_dev *hdev, int type, void *data,
> + int count, struct sk_buff **skb_ptr, gfp_t how)
> +{
so while reviewing this patch, I seems to make more sense to just give
an index to the reassembly SKB instead of trying to hand it as an extra
output parameter.
So reassembly[0] can be used for streams and [1..3] for packet specific
types then. That needs a small patch first to extend the array to 4
entries, but that should be just fine.
This meaning we do index = 0 for stream reassembly and index = type - 1
for packet type based reassembly.
Especially since this method is fully internal to bluetooth.ko I would
actually prefer this.
And "gfp_t gfp_mask" please.
> + int len = 0;
> + int header_len = 0;
We generally called this hlen.
> + int remain = count;
> + struct sk_buff *skb = *skb_ptr;
> + struct { struct bt_skb_cb cb_info; int expect; } *scb;
Why do we need this double scb. We could just extend our current
bt_skb_cb. Just put "u16 expect" after incoming.
Regards
Marcel
Implemented frame reassembly implementation for reassembling fragments
received from stream.
Signed-off-by: Suraj Sumangala <[email protected]>
---
include/net/bluetooth/hci_core.h | 2 ++
net/bluetooth/hci_core.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 600372d..345fc14 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -124,6 +124,7 @@ struct hci_dev {
struct sk_buff *sent_cmd;
struct sk_buff *reassembly[3];
+ struct sk_buff *stream_reassembly;
struct mutex req_lock;
wait_queue_head_t req_wait_q;
@@ -437,6 +438,7 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb);
int hci_recv_frame(struct sk_buff *skb);
int hci_recv_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 ca6182c..6025257 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -917,6 +917,8 @@ int hci_register_dev(struct hci_dev *hdev)
for (i = 0; i < 3; i++)
hdev->reassembly[i] = NULL;
+ hdev->stream_reassembly = NULL;
+
init_waitqueue_head(&hdev->req_wait_q);
mutex_init(&hdev->req_lock);
@@ -976,6 +978,8 @@ int hci_unregister_dev(struct hci_dev *hdev)
for (i = 0; i < 3; i++)
kfree_skb(hdev->reassembly[i]);
+ kfree_skb(hdev->stream_reassembly);
+
hci_notify(hdev, HCI_DEV_UNREG);
if (hdev->rfkill) {
@@ -1166,6 +1170,39 @@ int hci_recv_fragment(struct hci_dev *hdev, int type, void *data, int count)
}
EXPORT_SYMBOL(hci_recv_fragment);
+int hci_recv_stream_fragment(struct hci_dev *hdev, void *data, int count)
+{
+ int type;
+ int rem = 0;
+
+ do {
+ struct sk_buff *skb = hdev->stream_reassembly;
+ if (!skb) {
+ struct { char type; } *pkt;
+
+ /* Start of the frame */
+ pkt = data;
+ type = pkt->type;
+
+ data++;
+ count--;
+ } else
+ type = bt_cb(skb)->pkt_type;
+
+ rem = hci_reassembly(hdev, type, data, count, &skb, GFP_ATOMIC);
+ if (rem < 0)
+ return rem;
+
+ hdev->stream_reassembly = skb;
+
+ data += (count - rem);
+ count = rem;
+ } while (count);
+
+ return rem;
+}
+EXPORT_SYMBOL(hci_recv_stream_fragment);
+
/* ---- Interface to upper protocols ---- */
/* Register/Unregister protocols.
--
1.7.0.4
modified packet based reassembly function hci_recv_fragment() to use hci_reassembly()
Signed-off-by: Suraj Sumangala <[email protected]>
---
net/bluetooth/hci_core.c | 79 ++++++---------------------------------------
1 files changed, 11 insertions(+), 68 deletions(-)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index e1ede0b..ca6182c 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1144,82 +1144,25 @@ static int hci_reassembly(struct hci_dev *hdev, int type, void *data,
int hci_recv_fragment(struct hci_dev *hdev, int type, void *data, int count)
{
+ int rem = 0;
+
if (type < HCI_ACLDATA_PKT || type > HCI_EVENT_PKT)
return -EILSEQ;
- while (count) {
+ do {
struct sk_buff *skb = __reassembly(hdev, type);
- struct { int expect; } *scb;
- int len = 0;
-
- if (!skb) {
- /* Start of the frame */
-
- switch (type) {
- case HCI_EVENT_PKT:
- if (count >= HCI_EVENT_HDR_SIZE) {
- struct hci_event_hdr *h = data;
- len = HCI_EVENT_HDR_SIZE + h->plen;
- } else
- return -EILSEQ;
- break;
- case HCI_ACLDATA_PKT:
- if (count >= HCI_ACL_HDR_SIZE) {
- struct hci_acl_hdr *h = data;
- len = HCI_ACL_HDR_SIZE + __le16_to_cpu(h->dlen);
- } else
- return -EILSEQ;
- break;
+ rem = hci_reassembly(hdev, type, data, count, &skb, GFP_ATOMIC);
+ if (rem < 0)
+ return rem;
- case HCI_SCODATA_PKT:
- if (count >= HCI_SCO_HDR_SIZE) {
- struct hci_sco_hdr *h = data;
- len = HCI_SCO_HDR_SIZE + h->dlen;
- } else
- return -EILSEQ;
- break;
- }
+ __reassembly(hdev, type) = skb;
- skb = bt_skb_alloc(len, GFP_ATOMIC);
- if (!skb) {
- BT_ERR("%s no memory for packet", hdev->name);
- return -ENOMEM;
- }
-
- skb->dev = (void *) hdev;
- bt_cb(skb)->pkt_type = type;
-
- __reassembly(hdev, type) = skb;
-
- scb = (void *) skb->cb;
- scb->expect = len;
- } else {
- /* Continuation */
-
- scb = (void *) skb->cb;
- len = scb->expect;
- }
+ data += (count - rem);
+ count = rem;
+ } while (count);
- len = min(len, count);
-
- memcpy(skb_put(skb, len), data, len);
-
- scb->expect -= len;
-
- if (scb->expect == 0) {
- /* Complete frame */
-
- __reassembly(hdev, type) = NULL;
-
- bt_cb(skb)->pkt_type = type;
- hci_recv_frame(skb);
- }
-
- count -= len; data += len;
- }
-
- return 0;
+ return rem;
}
EXPORT_SYMBOL(hci_recv_fragment);
--
1.7.0.4