diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index fe668c1b9ced..6c790754ae3e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -129,6 +129,23 @@ int sysctl_tcp_invalid_ratelimit __read_mostly = HZ/2; #define REXMIT_LOST 1 /* retransmit packets marked lost */ #define REXMIT_NEW 2 /* FRTO-style transmit of unsent/new packets */ +static void tcp_gro_dev_warn(struct sock *sk, const struct sk_buff *skb) +{ + static bool __once __read_mostly; + + if (!__once) { + struct net_device *dev; + + __once = true; + + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif); + pr_warn("%s: Driver has suspect GRO implementation, TCP performance may be compromised.\n", + dev ? dev->name : "Unknown driver"); + rcu_read_unlock(); + } +} + /* Adapt the MSS value used to make delayed ack decision to the * real world. */ @@ -145,7 +162,10 @@ static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb) */ len = skb_shinfo(skb)->gso_size ? : skb->len; if (len >= icsk->icsk_ack.rcv_mss) { - icsk->icsk_ack.rcv_mss = len; + icsk->icsk_ack.rcv_mss = min_t(unsigned int, len, + tcp_sk(sk)->advmss); + if (unlikely(icsk->icsk_ack.rcv_mss != len)) + tcp_gro_dev_warn(sk, skb); } else { /* Otherwise, we make more careful check taking into account, * that SACKs block is variable. |