[PATCH v4 1/3] Implements hci_reassembly to reassemble Rx packets

[PATCH v4 1/3] Implements hci_reassembly to reassemble Rx packets

[suraj]

Implements feature to reassemble HCI frames received from an input stream.

Signed-off-by: Suraj Sumangala <suraj@atheros.com>
---
 net/bluetooth/hci_core.c |  115 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 115 insertions(+), 0 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 5e83f8e..3eb4c1b 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1030,6 +1030,121 @@ 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, int *remain)
+{
+	int len = 0;
+	int header_len = 0;
+	struct sk_buff *skb = *skb_ptr;
+	struct { struct bt_skb_cb cb_info; int expect; } *scb;
+
+	*remain = count;
+
+	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, GFP_ATOMIC);
+
+		if (!skb)
+			return -ENOMEM;
+
+		scb = (void *) skb->cb;
+		scb->expect = header_len;
+		scb->cb_info.pkt_type = (__u8)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 0;
+		}
+
+	}
+
+	return 0;
+}
 /* Receive packet type fragment */
 #define __reassembly(hdev, type)  ((hdev)->reassembly[(type) - 2])
 
-- 
1.7.0.4

[PATCH v4 2/3] Modified hci_recv_fragment() to use hci_reassembly

[suraj]

modified packet based reassembly function hci_recv_fragment() to use hci_reassembly()

Signed-off-by: Suraj Sumangala <suraj@atheros.com>
---
 net/bluetooth/hci_core.c |   78 +++++++--------------------------------------
 1 files changed, 12 insertions(+), 66 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 3eb4c1b..db6ca71 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1150,82 +1150,28 @@ 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 remaining = 0;
+	int err = 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;
+		err = hci_reassembly(hdev, type, data, count, &skb, &remaining);
 
-			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;
-			}
+		if (err < 0)
+			return err;
 
-			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;
 
-			__reassembly(hdev, type) = skb;
-
-			scb = (void *) skb->cb;
-			scb->expect = len;
-		} else {
-			/* Continuation */
-
-			scb = (void *) skb->cb;
-			len = scb->expect;
-		}
+		data += (count - remaining);
+		count = remaining;
 
-		len = min(len, count);
+	} while (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 err;
 }
 EXPORT_SYMBOL(hci_recv_fragment);
 
-- 
1.7.0.4

[PATCH v4 3/3] Implemented HCI frame reassembly for Rx from stream

[suraj]

Implemented frame reassembly implementation for reassembling fragments
received from stream.

Signed-off-by: Suraj Sumangala <suraj@atheros.com>
---
 include/net/bluetooth/hci_core.h |    2 +
 net/bluetooth/hci_core.c         |   43
++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h
b/include/net/bluetooth/hci_core.h
index e42f6ed..cd89d66 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -119,6 +119,7 @@ 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;
@@ -428,6 +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_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 db6ca71..ee75c42 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -916,6 +916,8 @@ 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);
 
@@ -973,6 +975,8 @@ 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) {
@@ -1145,6 +1149,45 @@ static int hci_reassembly(struct hci_dev *hdev,
int type, void *data,
 
 	return 0;
 }
+
+#define __stream_reassembly(hdev)  ((hdev)->stream_reassembly)
+
+int hci_recv_stream_fragment(struct hci_dev *hdev, void *data, int
count)
+{
+	int type;
+	int remaining = 0;
+	int err = 0;
+
+	do {
+		struct sk_buff *skb = __stream_reassembly(hdev);
+		if (!skb) {
+			struct { char type; } *pkt;
+
+			/* Start of the frame */
+			pkt = data;
+			type = pkt->type;
+
+			data++;
+			count--;
+		} else
+			type = bt_cb(skb)->pkt_type;
+
+		err = hci_reassembly(hdev, type, data, count, &skb, &remaining);
+
+		if (err < 0)
+			return err;
+
+		__stream_reassembly(hdev) = skb;
+
+		data += (count - remaining);
+		count = remaining;
+
+	} while (count);
+
+	return err;
+}
+EXPORT_SYMBOL(hci_recv_stream_fragment);
+
 /* Receive packet type fragment */
 #define __reassembly(hdev, type)  ((hdev)->reassembly[(type) - 2])
 
-- 
1.7.0.4

Re: [PATCH v4 3/3] Implemented HCI frame reassembly for Rx from stream

[Gustavo F. Padovan]

Hi Suraj,

* suraj <suraj@atheros.com> [2010-07-09 16:23:41 +0530]:

> Implemented frame reassembly implementation for reassembling fragments
> received from stream.
> 
> Signed-off-by: Suraj Sumangala <suraj@atheros.com>
> ---
>  include/net/bluetooth/hci_core.h |    2 +
>  net/bluetooth/hci_core.c         |   43
> ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 45 insertions(+), 0 deletions(-)
> 
> diff --git a/include/net/bluetooth/hci_core.h
> b/include/net/bluetooth/hci_core.h
> index e42f6ed..cd89d66 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -119,6 +119,7 @@ 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;
> @@ -428,6 +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_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 db6ca71..ee75c42 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -916,6 +916,8 @@ 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);
>  
> @@ -973,6 +975,8 @@ 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) {
> @@ -1145,6 +1149,45 @@ static int hci_reassembly(struct hci_dev *hdev,
> int type, void *data,
>  
>  	return 0;
>  }
> +
> +#define __stream_reassembly(hdev)  ((hdev)->stream_reassembly)

That's pointless. Your macro has about the same length of
hdev->stream_reassembly.

> +
> +int hci_recv_stream_fragment(struct hci_dev *hdev, void *data, int
> count)
> +{
> +	int type;
> +	int remaining = 0;
> +	int err = 0;
> +
> +	do {
> +		struct sk_buff *skb = __stream_reassembly(hdev);
> +		if (!skb) {
> +			struct { char type; } *pkt;
> +
> +			/* Start of the frame */
> +			pkt = data;
> +			type = pkt->type;
> +
> +			data++;
> +			count--;
> +		} else
> +			type = bt_cb(skb)->pkt_type;
> +
> +		err = hci_reassembly(hdev, type, data, count, &skb, &remaining);
> +
> +		if (err < 0)
> +			return err;
> +
> +		__stream_reassembly(hdev) = skb;
> +
> +		data += (count - remaining);
> +		count = remaining;
> +
> +	} while (count);
> +
> +	return err;
> +}
> +EXPORT_SYMBOL(hci_recv_stream_fragment);
> +
>  /* Receive packet type fragment */
>  #define __reassembly(hdev, type)  ((hdev)->reassembly[(type) - 2])
>  
> -- 
> 1.7.0.4
> 
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Gustavo F. Padovan
http://padovan.org

Re: [PATCH v4 1/3] Implements hci_reassembly to reassemble Rx packets

[Marcel Holtmann]

Hi Suraj,

you do need to fix your email or at least add a From: line. Otherwise
when I apply the patch this gets screwed up.

> Implements feature to reassemble HCI frames received from an input stream.
> 
> Signed-off-by: Suraj Sumangala <suraj@atheros.com>
> ---
>  net/bluetooth/hci_core.c |  115 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 115 insertions(+), 0 deletions(-)
> 
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 5e83f8e..3eb4c1b 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -1030,6 +1030,121 @@ 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, int *remain)

Why are we not not just return remain and err combined. Negative's are
errors positives are remains.

> +{
> +	int len = 0;
> +	int header_len = 0;
> +	struct sk_buff *skb = *skb_ptr;
> +	struct { struct bt_skb_cb cb_info; int expect; } *scb;
> +
> +	*remain = count;
> +
> +	if (type < HCI_ACLDATA_PKT || type > HCI_EVENT_PKT)
> +		return -EILSEQ;
> +
> +	if (!skb) {
> +
> +		switch (type) {

Remove this empty line here.

> +		case HCI_ACLDATA_PKT:
> +			len = HCI_MAX_FRAME_SIZE;
> +			header_len = HCI_ACL_HDR_SIZE;
> +		break;

The break needs to be on the same line as the code.

> +		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, GFP_ATOMIC);
> +
> +		if (!skb)

Remove the empty line here.

Do we always need GFP_ATOMIC here. I would prefer that we make that an
option of the function caller.

> +			return -ENOMEM;
> +
> +		scb = (void *) skb->cb;
> +		scb->expect = header_len;
> +		scb->cb_info.pkt_type = (__u8)type;

It is "(__u8) type" when casting.

> +
> +		skb->dev = (void *) hdev;
> +		*skb_ptr = skb;
> +
> +	}
> +
> +	while (count) {
> +
> +		scb = (void *) skb->cb;

Remove empty line here.

> +		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;

Remove this empty line.

> +				}
> +			}
> +			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;

Same here.

> +				}
> +			}
> +			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;

And here.

> +				}
> +			}
> +			break;
> +		}
> +
> +		if (scb->expect == 0) {
> +
> +			/* Complete frame */

Remove the empty line here.

> +			bt_cb(skb)->pkt_type = type;
> +			hci_recv_frame(skb);
> +
> +			*skb_ptr = NULL;
> +
> +			return 0;

And here.

> +		}
> +
> +	}

What is this empty line for. Please remove.

> +
> +	return 0;
> +}
>  /* Receive packet type fragment */

And here we need an extra empty line.

>  #define __reassembly(hdev, type)  ((hdev)->reassembly[(type) - 2])

Regards

Marcel