Bluetooth: Add bt_skb_sendmmsg helper

commit 97e4e80299844bb5f6ce5a7540742ffbffae3d97 upstream.

This works similarly to bt_skb_sendmsg but can split the msg into
multiple skb fragments which is useful for stream sockets.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 83eaa42..3275d57 100644 (file)
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -450,6 +450,44 @@ static inline struct sk_buff *bt_skb_sendmsg(struct sock *sk,
        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_OR_NULL(tmp)) {
+                       kfree_skb(skb);
+                       return tmp;
+               }
+
+               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);