mptcp: implement MSG_TRUNC support
The mentioned flag is currently silenlty ignored. This
change implements the TCP-like behaviour, dropping the
pending data up to the specified length.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Sigend-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1d5f23b..ae08c56 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1739,7 +1739,7 @@ static void mptcp_wait_data(struct sock *sk, long *timeo)
static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk,
struct msghdr *msg,
- size_t len)
+ size_t len, int flags)
{
struct sk_buff *skb;
int copied = 0;
@@ -1750,11 +1750,13 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk,
u32 count = min_t(size_t, len - copied, data_len);
int err;
- err = skb_copy_datagram_msg(skb, offset, msg, count);
- if (unlikely(err < 0)) {
- if (!copied)
- return err;
- break;
+ if (!(flags & MSG_TRUNC)) {
+ err = skb_copy_datagram_msg(skb, offset, msg, count);
+ if (unlikely(err < 0)) {
+ if (!copied)
+ return err;
+ break;
+ }
}
copied += count;
@@ -1966,7 +1968,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
while (copied < len) {
int bytes_read;
- bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied);
+ bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags);
if (unlikely(bytes_read < 0)) {
if (!copied)
copied = bytes_read;