When collapsing skbs during tcp_collapse_retrans and tcp_shift_skb_data,
this patch is to avoid collapsing to a prev skb that has eor_info mark
and the next_skb also has the tskey set (i.e. the prev skb will lose
a eor marked tskey info).
Signed-off-by: Martin KaFai Lau <ka...@fb.com>
Cc: Eric Dumazet <eduma...@google.com>
Cc: Neal Cardwell <ncardw...@google.com>
Cc: Soheil Hassas Yeganeh <soheil.k...@gmail.com>
Cc: Willem de Bruijn <will...@google.com>
Cc: Yuchung Cheng <ych...@google.com>
---
include/net/tcp.h | 6 ++++++
net/ipv4/tcp_input.c | 3 +++
net/ipv4/tcp_output.c | 7 +++++--
3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index f3c5dcb..56a287a 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -812,6 +812,12 @@ static inline int tcp_skb_mss(const struct sk_buff *skb)
return TCP_SKB_CB(skb)->tcp_gso_size;
}
+static inline bool tcp_skb_can_collapse_eor(const struct sk_buff *skb,
+ const struct sk_buff *next_skb)
+{
+ return !(TCP_SKB_CB(skb)->eor_info && skb_shinfo(next_skb)->tskey);
+}
+
/* Events passed to congestion control interface */
enum tcp_ca_event {
CA_EVENT_TX_START, /* first transmit when no packets in flight */
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 75e8336..e60922d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1368,6 +1368,9 @@ static struct sk_buff *tcp_shift_skb_data(struct sock
*sk, struct sk_buff *skb,
if ((TCP_SKB_CB(prev)->sacked & TCPCB_TAGBITS) != TCPCB_SACKED_ACKED)
goto fallback;
+ if (!tcp_skb_can_collapse_eor(prev, skb))
+ goto fallback;
+
in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) &&
!before(end_seq, TCP_SKB_CB(skb)->end_seq);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e71336c..1ae21f1 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2512,7 +2512,8 @@ static void tcp_collapse_retrans(struct sock *sk, struct
sk_buff *skb)
}
/* Check if coalescing SKBs is legal. */
-static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb)
+static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *to,
+ const struct sk_buff *skb)
{
if (tcp_skb_pcount(skb) > 1)
return false;
@@ -2526,6 +2527,8 @@ static bool tcp_can_collapse(const struct sock *sk, const
struct sk_buff *skb)
/* Some heurestics for collapsing over SACK'd could be invented */
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
return false;
+ if (!tcp_skb_can_collapse_eor(to, skb))
+ return false;
return true;
}
@@ -2546,7 +2549,7 @@ static void tcp_retrans_try_collapse(struct sock *sk,
struct sk_buff *to,
return;
tcp_for_write_queue_from_safe(skb, tmp, sk) {
- if (!tcp_can_collapse(sk, skb))
+ if (!tcp_can_collapse(sk, to, skb))
break;
space -= skb->len;
--
2.5.1
