2 files changed, 66 insertions, 0 deletions

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index fabee6db0..421d41ef4 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -370,6 +370,71 @@ out:
 	return NULL;
 }
 
+/* Shall not be called with lock_sock held */
+static inline struct sk_buff *bt_skb_sendmsg(struct sock *sk,
+					     struct msghdr *msg,
+					     size_t len, size_t mtu,
+					     size_t headroom, size_t tailroom)
+{
+	struct sk_buff *skb;
+	size_t size = min_t(size_t, len, mtu);
+	int err;
+
+	skb = bt_skb_send_alloc(sk, size + headroom + tailroom,
+				msg->msg_flags & MSG_DONTWAIT, &err);
+	if (!skb)
+		return ERR_PTR(err);
+
+	skb_reserve(skb, headroom);
+	skb_tailroom_reserve(skb, mtu, tailroom);
+
+	if (!copy_from_iter_full(skb_put(skb, size), size, &msg->msg_iter)) {
+		kfree_skb(skb);
+		return ERR_PTR(-EFAULT);
+	}
+
+	skb->priority = sk->sk_priority;
+
+	return skb;
+}
+
+/* Similar to bt_skb_sendmsg but can split the msg into multiple fragments
+ * accourding to the MTU.
+ */
+static inline struct sk_buff *bt_skb_sendmmsg(struct sock *sk,
+					      struct msghdr *msg,
+					      size_t len, size_t mtu,
+					      size_t headroom, size_t tailroom)
+{
+	struct sk_buff *skb, **frag;
+
+	skb = bt_skb_sendmsg(sk, msg, len, mtu, headroom, tailroom);
+	if (IS_ERR_OR_NULL(skb))
+		return skb;
+
+	len -= skb->len;
+	if (!len)
+		return skb;
+
+	/* Add remaining data over MTU as continuation fragments */
+	frag = &skb_shinfo(skb)->frag_list;
+	while (len) {
+		struct sk_buff *tmp;
+
+		tmp = bt_skb_sendmsg(sk, msg, len, mtu, headroom, tailroom);
+		if (IS_ERR(tmp)) {
+			return skb;
+		}
+
+		len -= tmp->len;
+
+		*frag = tmp;
+		frag = &(*frag)->next;
+	}
+
+	return skb;
+}
+
 int bt_to_errno(u16 code);
 
 void hci_sock_set_flag(struct sock *sk, int nr);
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 21dbd38f7..da0ef935c 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -798,6 +798,7 @@ enum {
 };
 
 void l2cap_chan_hold(struct l2cap_chan *c);
+struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c);
 void l2cap_chan_put(struct l2cap_chan *c);
 
 static inline void l2cap_chan_lock(struct l2cap_chan *chan)