@@ -138,8 +138,9 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock);
struct bt_skb_cb {
__u8 pkt_type;
__u8 incoming;
+ __u8 tx_seq;
};
-#define bt_cb(skb) ((struct bt_skb_cb *)(skb->cb))
+#define bt_cb(skb) ((struct bt_skb_cb *)((skb)->cb))
static inline struct sk_buff *bt_skb_alloc(unsigned int len, gfp_t how)
{
@@ -29,7 +29,8 @@
#define L2CAP_DEFAULT_MTU 672
#define L2CAP_DEFAULT_MIN_MTU 48
#define L2CAP_DEFAULT_FLUSH_TO 0xffff
-#define L2CAP_DEFAULT_TX_WINDOW 1
+#define L2CAP_DEFAULT_TX_WINDOW 63
+#define L2CAP_DEFAULT_NUM_TO_ACK (L2CAP_DEFAULT_TX_WINDOW/5)
#define L2CAP_DEFAULT_MAX_RECEIVE 1
#define L2CAP_DEFAULT_RETRANS_TO 300 /* 300 milliseconds */
#define L2CAP_DEFAULT_MONITOR_TO 1000 /* 1 second */
@@ -94,6 +95,31 @@ struct l2cap_conninfo {
#define L2CAP_FCS_NONE 0x00
#define L2CAP_FCS_CRC16 0x01
+/* L2CAP Control Field bit masks */
+#define L2CAP_CTRL_SAR 0xC000
+#define L2CAP_CTRL_REQSEQ 0x3F00
+#define L2CAP_CTRL_TXSEQ 0x007E
+#define L2CAP_CTRL_RETRANS 0x0080
+#define L2CAP_CTRL_FINAL 0x0080
+#define L2CAP_CTRL_POLL 0x0010
+#define L2CAP_CTRL_SUPERVISE 0x000C
+#define L2CAP_CTRL_FRAME_TYPE 0x0001 /* I- or S-Frame */
+
+#define L2CAP_CTRL_TXSEQ_SHIFT 1
+#define L2CAP_CTRL_REQSEQ_SHIFT 8
+
+/* L2CAP Supervisory Function */
+#define L2CAP_SUPER_RCV_READY 0x0000
+#define L2CAP_SUPER_REJECT 0x0004
+#define L2CAP_SUPER_RCV_NOT_READY 0x0008
+#define L2CAP_SUPER_SELECT_REJECT 0x000C
+
+/* L2CAP Segmentation and Reassembly */
+#define L2CAP_SDU_UNSEGMENTED 0x0000
+#define L2CAP_SDU_START 0x4000
+#define L2CAP_SDU_END 0x8000
+#define L2CAP_SDU_CONTINUE 0xC000
+
/* L2CAP structures */
struct l2cap_hdr {
__le16 len;
@@ -262,6 +288,7 @@ struct l2cap_conn {
/* ----- L2CAP channel and socket info ----- */
#define l2cap_pi(sk) ((struct l2cap_pinfo *) sk)
+#define TX_QUEUE(sk) (&l2cap_pi(sk)->tx_queue)
struct l2cap_pinfo {
struct bt_sock bt;
@@ -285,6 +312,13 @@ struct l2cap_pinfo {
__u8 conf_len;
__u8 conf_state;
+ __u8 next_tx_seq;
+ __u8 expected_ack_seq;
+ __u8 req_seq;
+ __u8 expected_tx_seq;
+ __u8 unacked_frames;
+ __u8 num_to_ack;
+
__u8 ident;
__u8 remote_tx_win;
@@ -295,6 +329,7 @@ struct l2cap_pinfo {
__le16 sport;
+ struct sk_buff_head tx_queue;
struct l2cap_conn *conn;
struct sock *next_c;
struct sock *prev_c;
@@ -311,6 +346,23 @@ struct l2cap_pinfo {
#define L2CAP_CONF_MAX_CONF_REQ 2
#define L2CAP_CONF_MAX_CONF_RSP 2
+static inline int l2cap_tx_window_full(struct sock *sk)
+{
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+ int sub;
+
+ sub = (pi->next_tx_seq - pi->expected_ack_seq) % 64;
+
+ if (sub < 0)
+ sub += 64;
+
+ return (sub == pi->remote_tx_win);
+}
+
+#define __get_txseq(ctrl) ((ctrl) & L2CAP_CTRL_TXSEQ) >> 1
+#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
void l2cap_load(void);
@@ -333,6 +333,30 @@ static inline int l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16
return hci_send_acl(conn->hcon, skb, 0);
}
+static inline int l2cap_send_sframe(struct l2cap_pinfo *pi, u16 control)
+{
+ struct sk_buff *skb;
+ struct l2cap_hdr *lh;
+ struct l2cap_conn *conn = pi->conn;
+ int count;
+
+ BT_DBG("pi %p, control 0x%2.2x", pi, control);
+
+ count = min_t(unsigned int, conn->mtu, L2CAP_HDR_SIZE + 2);
+ control |= L2CAP_CTRL_FRAME_TYPE;
+
+ skb = bt_skb_alloc(count, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
+ lh->len = cpu_to_le16(2);
+ lh->cid = cpu_to_le16(pi->dcid);
+ put_unaligned_le16(control, skb_put(skb, 2));
+
+ return hci_send_acl(pi->conn->hcon, skb, 0);
+}
+
static void l2cap_do_start(struct sock *sk)
{
struct l2cap_conn *conn = l2cap_pi(sk)->conn;
@@ -1154,39 +1178,80 @@ static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, int *l
return 0;
}
-static inline int l2cap_do_send(struct sock *sk, struct msghdr *msg, int len)
+static void l2cap_drop_acked_frames(struct sock *sk)
{
- struct l2cap_conn *conn = l2cap_pi(sk)->conn;
- struct sk_buff *skb, **frag;
- int err, hlen, count, sent = 0;
- struct l2cap_hdr *lh;
+ struct sk_buff *skb;
- BT_DBG("sk %p len %d", sk, len);
+ while ((skb = skb_peek(TX_QUEUE(sk)))) {
+ if (bt_cb(skb)->tx_seq == l2cap_pi(sk)->expected_ack_seq)
+ break;
- /* First fragment (with L2CAP header) */
- if (sk->sk_type == SOCK_DGRAM)
- hlen = L2CAP_HDR_SIZE + 2;
- else
- hlen = L2CAP_HDR_SIZE;
+ skb = skb_dequeue(TX_QUEUE(sk));
+ kfree_skb(skb);
- count = min_t(unsigned int, (conn->mtu - hlen), len);
+ l2cap_pi(sk)->unacked_frames--;
+ }
- skb = bt_skb_send_alloc(sk, hlen + count,
- msg->msg_flags & MSG_DONTWAIT, &err);
- if (!skb)
- return err;
+ return;
+}
- /* Create L2CAP header */
- lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
- lh->cid = cpu_to_le16(l2cap_pi(sk)->dcid);
- lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+static inline int l2cap_do_send(struct sock *sk, struct sk_buff *skb)
+{
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+ int err;
+
+ BT_DBG("sk %p, skb %p len %d", sk, skb, skb->len);
+
+ err = hci_send_acl(pi->conn->hcon, skb, 0);
+ if (err < 0)
+ kfree_skb(skb);
+
+ return err;
+}
+
+static int l2cap_ertm_send(struct sock *sk)
+{
+ struct sk_buff *skb, *tx_skb;
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+ u16 control;
+ int err;
+
+ while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk))) {
+ tx_skb = skb_clone(skb, GFP_ATOMIC);
- if (sk->sk_type == SOCK_DGRAM)
- put_unaligned(l2cap_pi(sk)->psm, (__le16 *) skb_put(skb, 2));
+ control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+ control |= (pi->req_seq << L2CAP_CTRL_REQSEQ_SHIFT)
+ | (pi->next_tx_seq << L2CAP_CTRL_TXSEQ_SHIFT);
+ put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
+
+ err = l2cap_do_send(sk, tx_skb);
+ if (err < 0) {
+ l2cap_send_disconn_req(pi->conn, sk);
+ return err;
+ }
+
+ bt_cb(skb)->tx_seq = pi->next_tx_seq;
+ pi->next_tx_seq = (pi->next_tx_seq + 1) % 64;
+
+ pi->unacked_frames++;
+
+ if (skb_queue_is_last(TX_QUEUE(sk), skb))
+ sk->sk_send_head = NULL;
+ else
+ sk->sk_send_head = skb_queue_next(TX_QUEUE(sk), skb);
+ }
+
+ return 0;
+}
+
+static inline int l2cap_skbuff_fromiovec(struct sock *sk, struct msghdr *msg, int len, int count, struct sk_buff *skb)
+{
+ struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+ struct sk_buff **frag;
+ int err, sent = 0;
if (memcpy_fromiovec(skb_put(skb, count), msg->msg_iov, count)) {
- err = -EFAULT;
- goto fail;
+ return -EFAULT;
}
sent += count;
@@ -1199,33 +1264,112 @@ static inline int l2cap_do_send(struct sock *sk, struct msghdr *msg, int len)
*frag = bt_skb_send_alloc(sk, count, msg->msg_flags & MSG_DONTWAIT, &err);
if (!*frag)
- goto fail;
-
- if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count)) {
- err = -EFAULT;
- goto fail;
- }
+ return -EFAULT;
+ if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count))
+ return -EFAULT;
sent += count;
len -= count;
frag = &(*frag)->next;
}
- err = hci_send_acl(conn->hcon, skb, 0);
- if (err < 0)
- goto fail;
return sent;
+}
-fail:
- kfree_skb(skb);
- return err;
+static struct sk_buff *l2cap_create_connless_pdu(struct sock *sk, struct msghdr *msg, size_t len)
+{
+ struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+ struct sk_buff *skb;
+ int err, count, hlen = L2CAP_HDR_SIZE + 2;
+ struct l2cap_hdr *lh;
+
+ BT_DBG("sk %p len %d", sk, (int)len);
+
+ count = min_t(unsigned int, (conn->mtu - hlen), len);
+ skb = bt_skb_send_alloc(sk, count + hlen,
+ msg->msg_flags & MSG_DONTWAIT, &err);
+ if (!skb)
+ return ERR_PTR(-ENOMEM);
+
+ /* Create L2CAP header */
+ lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
+ lh->cid = cpu_to_le16(l2cap_pi(sk)->dcid);
+ lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+ put_unaligned_le16(l2cap_pi(sk)->psm, skb_put(skb, 2));
+
+ err = l2cap_skbuff_fromiovec(sk, msg, len, count, skb);
+ if (unlikely(err < 0)) {
+ kfree_skb(skb);
+ return ERR_PTR(err);
+ }
+ return skb;
+}
+
+static struct sk_buff *l2cap_create_basic_pdu(struct sock *sk, struct msghdr *msg, size_t len)
+{
+ struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+ struct sk_buff *skb;
+ int err, count, hlen = L2CAP_HDR_SIZE;
+ struct l2cap_hdr *lh;
+
+ BT_DBG("sk %p len %d", sk, (int)len);
+
+ count = min_t(unsigned int, (conn->mtu - hlen), len);
+ skb = bt_skb_send_alloc(sk, count + hlen,
+ msg->msg_flags & MSG_DONTWAIT, &err);
+ if (!skb)
+ return ERR_PTR(-ENOMEM);
+
+ /* Create L2CAP header */
+ lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
+ lh->cid = cpu_to_le16(l2cap_pi(sk)->dcid);
+ lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+
+ err = l2cap_skbuff_fromiovec(sk, msg, len, count, skb);
+ if (unlikely(err < 0)) {
+ kfree_skb(skb);
+ return ERR_PTR(err);
+ }
+ return skb;
+}
+
+static struct sk_buff *l2cap_create_ertm_pdu(struct sock *sk, struct msghdr *msg, size_t len, u16 control)
+{
+ struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+ struct sk_buff *skb;
+ int err, count, hlen = L2CAP_HDR_SIZE + 2;
+ struct l2cap_hdr *lh;
+
+ BT_DBG("sk %p len %d", sk, (int)len);
+
+ count = min_t(unsigned int, (conn->mtu - hlen), len);
+ skb = bt_skb_send_alloc(sk, count + hlen,
+ msg->msg_flags & MSG_DONTWAIT, &err);
+ if (!skb)
+ return ERR_PTR(-ENOMEM);
+
+ /* Create L2CAP header */
+ lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
+ lh->cid = cpu_to_le16(l2cap_pi(sk)->dcid);
+ lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+ put_unaligned_le16(control, skb_put(skb, 2));
+
+ err = l2cap_skbuff_fromiovec(sk, msg, len, count, skb);
+ if (unlikely(err < 0)) {
+ kfree_skb(skb);
+ return ERR_PTR(err);
+ }
+ return skb;
}
static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
- int err = 0;
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+ struct sk_buff *skb;
+ u16 control;
+ int err;
BT_DBG("sock %p, sk %p", sock, sk);
@@ -1237,16 +1381,67 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
return -EOPNOTSUPP;
/* Check outgoing MTU */
- if (sk->sk_type != SOCK_RAW && len > l2cap_pi(sk)->omtu)
+ if (sk->sk_type == SOCK_SEQPACKET && pi->mode == L2CAP_MODE_BASIC
+ && len > pi->omtu)
return -EINVAL;
lock_sock(sk);
- if (sk->sk_state == BT_CONNECTED)
- err = l2cap_do_send(sk, msg, len);
- else
+ if (sk->sk_state != BT_CONNECTED) {
err = -ENOTCONN;
+ goto done;
+ }
+
+ /* Connectionless channel */
+ if (sk->sk_type == SOCK_DGRAM) {
+ skb = l2cap_create_connless_pdu(sk, msg, len);
+ err = l2cap_do_send(sk, skb);
+ goto done;
+ }
+ switch (pi->mode) {
+ case L2CAP_MODE_BASIC:
+ /* Create a basic PDU */
+ skb = l2cap_create_basic_pdu(sk, msg, len);
+ if (IS_ERR(skb)) {
+ err = PTR_ERR(skb);
+ goto done;
+ }
+
+ err = l2cap_do_send(sk, skb);
+ if (!err)
+ err = len;
+ break;
+
+ case L2CAP_MODE_ERTM:
+ /* Entire SDU fits into one PDU */
+ if (len <= pi->omtu) {
+ control = L2CAP_SDU_UNSEGMENTED;
+ skb = l2cap_create_ertm_pdu(sk, msg, len, control);
+ if (IS_ERR(skb)) {
+ err = PTR_ERR(skb);
+ goto done;
+ }
+ } else {
+ /* FIXME: Segmentation will be added later */
+ err = -EINVAL;
+ goto done;
+ }
+ __skb_queue_tail(TX_QUEUE(sk), skb);
+ if (sk->sk_send_head == NULL)
+ sk->sk_send_head = skb;
+
+ err = l2cap_ertm_send(sk);
+ if (!err)
+ err = len;
+ break;
+
+ default:
+ BT_DBG("bad state %1.1x", pi->mode);
+ err = -EINVAL;
+ }
+
+done:
release_sock(sk);
return err;
}
@@ -2301,6 +2496,10 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
sk->sk_state = BT_CONNECTED;
+ l2cap_pi(sk)->next_tx_seq = 0;
+ l2cap_pi(sk)->expected_ack_seq = 0;
+ l2cap_pi(sk)->unacked_frames = 0;
+ __skb_queue_head_init(TX_QUEUE(sk));
l2cap_chan_ready(sk);
goto unlock;
}
@@ -2375,6 +2574,9 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
if (l2cap_pi(sk)->conf_state & L2CAP_CONF_OUTPUT_DONE) {
sk->sk_state = BT_CONNECTED;
+ l2cap_pi(sk)->expected_tx_seq = 0;
+ l2cap_pi(sk)->num_to_ack = 0;
+ __skb_queue_head_init(TX_QUEUE(sk));
l2cap_chan_ready(sk);
}
@@ -2405,6 +2607,8 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
sk->sk_shutdown = SHUTDOWN_MASK;
+ skb_queue_purge(TX_QUEUE(sk));
+
l2cap_chan_del(sk, ECONNRESET);
bh_unlock_sock(sk);
@@ -2427,6 +2631,8 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
if (!sk)
return 0;
+ skb_queue_purge(TX_QUEUE(sk));
+
l2cap_chan_del(sk, 0);
bh_unlock_sock(sk);
@@ -2602,9 +2808,60 @@ static inline void l2cap_sig_channel(struct l2cap_conn *conn, struct sk_buff *sk
kfree_skb(skb);
}
+static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, struct sk_buff *skb)
+{
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+ u8 tx_seq = __get_txseq(rx_control);
+ u16 tx_control = 0;
+ int err = 0;
+
+ BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len);
+
+ if (tx_seq != pi->expected_tx_seq)
+ return -EINVAL;
+
+ pi->expected_tx_seq = (pi->expected_tx_seq + 1) % 64;
+ err = sock_queue_rcv_skb(sk, skb);
+ if (err)
+ return err;
+
+ pi->num_to_ack = (pi->num_to_ack + 1) % L2CAP_DEFAULT_NUM_TO_ACK;
+ if (pi->num_to_ack == L2CAP_DEFAULT_NUM_TO_ACK - 1) {
+ tx_control |= L2CAP_CTRL_FRAME_TYPE;
+ tx_control |= L2CAP_SUPER_RCV_READY;
+ tx_control |= pi->expected_tx_seq << L2CAP_CTRL_REQSEQ_SHIFT;
+ err = l2cap_send_sframe(pi, tx_control);
+ }
+ return err;
+}
+
+static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, struct sk_buff *skb)
+{
+ struct l2cap_pinfo *pi = l2cap_pi(sk);
+
+ BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len);
+
+ switch (rx_control & L2CAP_CTRL_SUPERVISE) {
+ case L2CAP_SUPER_RCV_READY:
+ pi->expected_ack_seq = __get_reqseq(rx_control);
+ l2cap_drop_acked_frames(sk);
+ l2cap_ertm_send(sk);
+ break;
+
+ case L2CAP_SUPER_RCV_NOT_READY:
+ case L2CAP_SUPER_REJECT:
+ case L2CAP_SUPER_SELECT_REJECT:
+ break;
+ }
+
+ return 0;
+}
+
static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk_buff *skb)
{
struct sock *sk;
+ u16 control;
+ int err;
sk = l2cap_get_chan_by_scid(&conn->chan_list, cid);
if (!sk) {
@@ -2617,16 +2874,40 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
if (sk->sk_state != BT_CONNECTED)
goto drop;
- if (l2cap_pi(sk)->imtu < skb->len)
- goto drop;
+ switch (l2cap_pi(sk)->mode) {
+ case L2CAP_MODE_BASIC:
+ /* If socket recv buffers overflows we drop data here
+ * which is *bad* because L2CAP has to be reliable.
+ * But we don't have any other choice. L2CAP doesn't
+ * provide flow control mechanism. */
- /* If socket recv buffers overflows we drop data here
- * which is *bad* because L2CAP has to be reliable.
- * But we don't have any other choice. L2CAP doesn't
- * provide flow control mechanism. */
+ if (l2cap_pi(sk)->imtu < skb->len)
+ goto drop;
- if (!sock_queue_rcv_skb(sk, skb))
- goto done;
+ if (!sock_queue_rcv_skb(sk, skb))
+ goto done;
+ break;
+
+ case L2CAP_MODE_ERTM:
+ control = get_unaligned_le16(skb->data);
+ skb_pull(skb, 2);
+
+ if (l2cap_pi(sk)->imtu < skb->len)
+ goto drop;
+
+ if (__is_iframe(control))
+ err = l2cap_data_channel_iframe(sk, control, skb);
+ else
+ err = l2cap_data_channel_sframe(sk, control, skb);
+
+ if (!err)
+ goto done;
+ break;
+
+ default:
+ BT_DBG("sk %p: bad mode 0x%2.2x", sk, l2cap_pi(sk)->mode);
+ break;
+ }
drop:
kfree_skb(skb);
@@ -2676,6 +2957,11 @@ static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
cid = __le16_to_cpu(lh->cid);
len = __le16_to_cpu(lh->len);
+ if (len != skb->len) {
+ kfree_skb(skb);
+ return;
+ }
+
BT_DBG("len %d, cid 0x%4.4x", len, cid);
switch (cid) {