Bluetooth: Add bt_skb_sendmsg helper

bt_skb_sendmsg helps takes care of allocation the skb and copying the
the contents of msg over to the skb while checking for possible errors
so it should be safe to call it without holding lock_sock.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 0a5f98081581a84e107656e99d60142fbb310a3f..11020b12a6edba9a7a09e951eaf5d253fc634a0c 100644 (file)
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -444,6 +444,34 @@ 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;
+}
+
 int bt_to_errno(u16 code);
 
 void hci_sock_set_flag(struct sock *sk, int nr);