Bluetooth: Add support for Segmentation and Reassembly of SDUs

ERTM should use Segmentation and Reassembly to break down a SDU in many
PDUs on sending data to the other side.

On sending packets we queue all 'segments' until end of segmentation and
just the add them to the queue for sending. On receiving we create a new
SKB with the SDU reassembled.

Initially based on a patch from Nathan Holstein <nathan@lampreynetworks.com>

Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 9bbfbe74d400..0afde8d22b56 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -34,7 +34,7 @@
 #define L2CAP_DEFAULT_MAX_RECEIVE       1
 #define L2CAP_DEFAULT_RETRANS_TO        300    /* 300 milliseconds */
 #define L2CAP_DEFAULT_MONITOR_TO        1000   /* 1 second */
-#define L2CAP_DEFAULT_MAX_RX_APDU       0xfff7
+#define L2CAP_DEFAULT_MAX_PDU_SIZE      672
 
 #define L2CAP_CONN_TIMEOUT      (40000) /* 40 seconds */
 #define L2CAP_INFO_TIMEOUT      (4000)  /*  4 seconds */
@@ -311,6 +311,7 @@ struct l2cap_pinfo {
         __u8            conf_req[64];
         __u8            conf_len;
         __u8            conf_state;
+        __u8            conn_state;
 
         __u8            next_tx_seq;
         __u8            expected_ack_seq;
@@ -318,6 +319,9 @@ struct l2cap_pinfo {
         __u8            expected_tx_seq;
         __u8            unacked_frames;
         __u8            num_to_ack;
+        __u16           sdu_len;
+        __u16           partial_sdu_len;
+        struct sk_buff  *sdu;
 
         __u8            ident;
 
@@ -346,6 +350,8 @@ struct l2cap_pinfo {
 #define L2CAP_CONF_MAX_CONF_REQ 2
 #define L2CAP_CONF_MAX_CONF_RSP 2
 
+#define L2CAP_CONN_SAR_SDU         0x01
+
 static inline int l2cap_tx_window_full(struct sock *sk)
 {
         struct l2cap_pinfo *pi = l2cap_pi(sk);
@@ -363,6 +369,7 @@ static inline int l2cap_tx_window_full(struct sock *sk)
 #define __get_reqseq(ctrl) ((ctrl) & L2CAP_CTRL_REQSEQ) >> 8
 #define __is_iframe(ctrl) !((ctrl) & L2CAP_CTRL_FRAME_TYPE)
 #define __is_sframe(ctrl) (ctrl) & L2CAP_CTRL_FRAME_TYPE
+#define __is_sar_start(ctrl) ((ctrl) & L2CAP_CTRL_SAR) == L2CAP_SDU_START
 
 void l2cap_load(void);