diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index eaa9582..4fee042 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -346,8 +346,6 @@ static inline void tcp_dec_quickack_mode(struct sock *sk, } } -extern void tcp_enter_quickack_mode(struct sock *sk); - #define TCP_ECN_OK 1 #define TCP_ECN_QUEUE_CWR 2 #define TCP_ECN_DEMAND_CWR 4 @@ -475,8 +473,22 @@ extern unsigned int tcp_current_mss(struct sock *sk); /* Bound MSS / TSO packet size with the half of the window */ static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) { - if (tp->max_window && pktsize > (tp->max_window >> 1)) - return max(tp->max_window >> 1, 68U - tp->tcp_header_len); + int cutoff; + + /* When peer uses tiny windows, there is no use in packetizing + * to sub-MSS pieces for the sake of SWS or making sure there + * are enough packets in the pipe for fast recovery. + * + * On the other hand, for extremely large MSS devices, handling + * smaller than MSS windows in this way does make sense. + */ + if (tp->max_window >= 512) + cutoff = (tp->max_window >> 1); + else + cutoff = tp->max_window; + + if (cutoff && pktsize > cutoff) + return max_t(int, cutoff, 68U - tp->tcp_header_len); else return pktsize; } @@ -789,6 +801,15 @@ static inline __u32 tcp_current_ssthresh(const struct sock *sk) /* Use define here intentionally to get WARN_ON location shown at the caller */ #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) +/* + * Convert RFC 3390 larger initial window into an equivalent number of packets. + * This is based on the numbers specified in RFC 5681, 3.1. + */ +static inline u32 rfc3390_bytes_to_packets(const u32 smss) +{ + return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3); +} + extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh); extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst); |