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Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r--net/ipv4/tcp_output.c35
1 files changed, 23 insertions, 12 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index fd0cea114b5..509912a5ff9 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1298,7 +1298,6 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
eat = min_t(int, len, skb_headlen(skb));
if (eat) {
__skb_pull(skb, eat);
- skb->avail_size -= eat;
len -= eat;
if (!len)
return;
@@ -1351,8 +1350,8 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
return 0;
}
-/* Calculate MSS. Not accounting for SACKs here. */
-int tcp_mtu_to_mss(struct sock *sk, int pmtu)
+/* Calculate MSS not accounting any TCP options. */
+static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu)
{
const struct tcp_sock *tp = tcp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1381,13 +1380,17 @@ int tcp_mtu_to_mss(struct sock *sk, int pmtu)
/* Then reserve room for full set of TCP options and 8 bytes of data */
if (mss_now < 48)
mss_now = 48;
-
- /* Now subtract TCP options size, not including SACKs */
- mss_now -= tp->tcp_header_len - sizeof(struct tcphdr);
-
return mss_now;
}
+/* Calculate MSS. Not accounting for SACKs here. */
+int tcp_mtu_to_mss(struct sock *sk, int pmtu)
+{
+ /* Subtract TCP options size, not including SACKs */
+ return __tcp_mtu_to_mss(sk, pmtu) -
+ (tcp_sk(sk)->tcp_header_len - sizeof(struct tcphdr));
+}
+
/* Inverse of above */
int tcp_mss_to_mtu(struct sock *sk, int mss)
{
@@ -1806,8 +1809,11 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
goto send_now;
}
- /* Ok, it looks like it is advisable to defer. */
- tp->tso_deferred = 1 | (jiffies << 1);
+ /* Ok, it looks like it is advisable to defer.
+ * Do not rearm the timer if already set to not break TCP ACK clocking.
+ */
+ if (!tp->tso_deferred)
+ tp->tso_deferred = 1 | (jiffies << 1);
return true;
@@ -2382,8 +2388,12 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
*/
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- /* make sure skb->data is aligned on arches that require it */
- if (unlikely(NET_IP_ALIGN && ((unsigned long)skb->data & 3))) {
+ /* make sure skb->data is aligned on arches that require it
+ * and check if ack-trimming & collapsing extended the headroom
+ * beyond what csum_start can cover.
+ */
+ if (unlikely((NET_IP_ALIGN && ((unsigned long)skb->data & 3)) ||
+ skb_headroom(skb) >= 0xFFFF)) {
struct sk_buff *nskb = __pskb_copy(skb, MAX_TCP_HEADER,
GFP_ATOMIC);
return nskb ? tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC) :
@@ -2703,6 +2713,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
skb_reserve(skb, MAX_TCP_HEADER);
skb_dst_set(skb, dst);
+ security_skb_owned_by(skb, sk);
mss = dst_metric_advmss(dst);
if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
@@ -2930,7 +2941,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
*/
if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->rx_opt.mss_clamp)
tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
- space = tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) -
+ space = __tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) -
MAX_TCP_OPTION_SPACE;
syn_data = skb_copy_expand(syn, skb_headroom(syn), space,