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authorGustavo F. Padovan <padovan@profusion.mobi>2010-06-21 18:53:22 -0300
committerMarcel Holtmann <marcel@holtmann.org>2010-07-21 10:39:09 -0700
commit218bb9dfd21472128f86b38ad2eab123205c2991 (patch)
treea380097efa336c128a81460c9f316f04f39aeadc /net/bluetooth
parente0f66218b3a7d0bcf37ca95186123c257fda0ba5 (diff)
Bluetooth: Add backlog queue to ERTM code
backlog queue is the canonical mechanism to avoid race conditions due interrupts in bottom half context. After the socket lock is released the net core take care of push all skb in its backlog queue. Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/l2cap.c132
1 files changed, 79 insertions, 53 deletions
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index dc8601fc2404..cf4481f7f566 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -77,6 +77,8 @@ static void l2cap_sock_kill(struct sock *sk);
static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
u8 code, u8 ident, u16 dlen, void *data);
+static int l2cap_ertm_data_rcv(struct sock *sk, struct sk_buff *skb);
+
/* ---- L2CAP timers ---- */
static void l2cap_sock_timeout(unsigned long arg)
{
@@ -2447,6 +2449,8 @@ static inline void l2cap_ertm_init(struct sock *sk)
__skb_queue_head_init(BUSY_QUEUE(sk));
INIT_WORK(&l2cap_pi(sk)->busy_work, l2cap_busy_work);
+
+ sk->sk_backlog_rcv = l2cap_ertm_data_rcv;
}
static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
@@ -4171,13 +4175,83 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
return 0;
}
+static int l2cap_ertm_data_rcv(struct sock *sk, struct sk_buff *skb)
+{
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+ u16 control;
+ u8 req_seq;
+ int len, next_tx_seq_offset, req_seq_offset;
+
+ control = get_unaligned_le16(skb->data);
+ skb_pull(skb, 2);
+ len = skb->len;
+
+ /*
+ * We can just drop the corrupted I-frame here.
+ * Receiver will miss it and start proper recovery
+ * procedures and ask retransmission.
+ */
+ if (l2cap_check_fcs(pi, skb))
+ goto drop;
+
+ if (__is_sar_start(control) && __is_iframe(control))
+ len -= 2;
+
+ if (pi->fcs == L2CAP_FCS_CRC16)
+ len -= 2;
+
+ if (len > pi->mps) {
+ l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+ goto drop;
+ }
+
+ req_seq = __get_reqseq(control);
+ req_seq_offset = (req_seq - pi->expected_ack_seq) % 64;
+ if (req_seq_offset < 0)
+ req_seq_offset += 64;
+
+ next_tx_seq_offset =
+ (pi->next_tx_seq - pi->expected_ack_seq) % 64;
+ if (next_tx_seq_offset < 0)
+ next_tx_seq_offset += 64;
+
+ /* check for invalid req-seq */
+ if (req_seq_offset > next_tx_seq_offset) {
+ l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+ goto drop;
+ }
+
+ if (__is_iframe(control)) {
+ if (len < 0) {
+ l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+ goto drop;
+ }
+
+ l2cap_data_channel_iframe(sk, control, skb);
+ } else {
+ if (len != 0) {
+ BT_ERR("%d", len);
+ l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+ goto drop;
+ }
+
+ l2cap_data_channel_sframe(sk, control, skb);
+ }
+
+ return 0;
+
+drop:
+ kfree_skb(skb);
+ return 0;
+}
+
static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk_buff *skb)
{
struct sock *sk;
struct l2cap_pinfo *pi;
u16 control;
- u8 tx_seq, req_seq;
- int len, next_tx_seq_offset, req_seq_offset;
+ u8 tx_seq;
+ int len;
sk = l2cap_get_chan_by_scid(&conn->chan_list, cid);
if (!sk) {
@@ -4207,59 +4281,11 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
break;
case L2CAP_MODE_ERTM:
- control = get_unaligned_le16(skb->data);
- skb_pull(skb, 2);
- len = skb->len;
-
- /*
- * We can just drop the corrupted I-frame here.
- * Receiver will miss it and start proper recovery
- * procedures and ask retransmission.
- */
- if (l2cap_check_fcs(pi, skb))
- goto drop;
-
- if (__is_sar_start(control) && __is_iframe(control))
- len -= 2;
-
- if (pi->fcs == L2CAP_FCS_CRC16)
- len -= 2;
-
- if (len > pi->mps) {
- l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
- goto drop;
- }
-
- req_seq = __get_reqseq(control);
- req_seq_offset = (req_seq - pi->expected_ack_seq) % 64;
- if (req_seq_offset < 0)
- req_seq_offset += 64;
-
- next_tx_seq_offset =
- (pi->next_tx_seq - pi->expected_ack_seq) % 64;
- if (next_tx_seq_offset < 0)
- next_tx_seq_offset += 64;
-
- /* check for invalid req-seq */
- if (req_seq_offset > next_tx_seq_offset) {
- l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
- goto drop;
- }
-
- if (__is_iframe(control)) {
- if (len < 0) {
- l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
- goto drop;
- }
-
- l2cap_data_channel_iframe(sk, control, skb);
+ if (!sock_owned_by_user(sk)) {
+ l2cap_ertm_data_rcv(sk, skb);
} else {
- if (len != 0) {
- l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+ if (sk_add_backlog(sk, skb))
goto drop;
- }
-
- l2cap_data_channel_sframe(sk, control, skb);
}
goto done;

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