tcp: coalesce/collapse must respect MPTCP extensions
Coalesce and collapse of packets carrying MPTCP extensions is allowed
when the newer packet has no extension or the extensions carried by both
packets are equal.
This allows merging of TSO packet trains and even cross-TSO packets, and
does not require any additional action when moving data into existing
SKBs.
v3 -> v4:
- allow collapsing, under mptcp_skb_can_collapse() constraint
v5 -> v6:
- clarify MPTCP skb extensions must always be cleared at allocation
time
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index ac52633..13bc83f 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -39,6 +39,7 @@
#include <net/tcp_states.h>
#include <net/inet_ecn.h>
#include <net/dst.h>
+#include <net/mptcp.h>
#include <linux/seq_file.h>
#include <linux/memcontrol.h>
@@ -978,6 +979,13 @@ static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb)
return likely(!TCP_SKB_CB(skb)->eor);
}
+static inline bool tcp_skb_can_collapse(const struct sk_buff *to,
+ const struct sk_buff *from)
+{
+ return likely(tcp_skb_can_collapse_to(to) &&
+ mptcp_skb_can_collapse(to, from));
+}
+
/* Events passed to congestion control interface */
enum tcp_ca_event {
CA_EVENT_TX_START, /* first transmit when no packets in flight */