diff options
| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2010-08-29 19:23:12 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-08-30 13:45:26 -0700 |
| commit | 22b71c8f4f3db8df92f5e7b081c265bc56c0bd2f (patch) | |
| tree | b913f63369b09ad703ed52a42b367455785ef3af /include/net/tcp.h | |
| parent | d26eeb07fd02de31848b59d19687daff0e93532f (diff) | |
tcp/dccp: Consolidate common code for RFC 3390 conversion
This patch consolidates initial-window code common to TCP and CCID-2:
* TCP uses RFC 3390 in a packet-oriented manner (tcp_input.c) and
* CCID-2 uses RFC 3390 in packet-oriented manner (RFC 4341).
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index df6a2eb2019..a64022199b6 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -779,6 +779,21 @@ 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. + * + * John Heffner states: + * + * The RFC specifies a window of no more than 4380 bytes + * unless 2*MSS > 4380. Reading the pseudocode in the RFC + * is a bit misleading because they use a clamp at 4380 bytes + * rather than a multiplier in the relevant range. + */ +static inline u32 rfc3390_bytes_to_packets(const u32 smss) +{ + return smss <= 1095 ? 4 : (smss > 1460 ? 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); |