samsung_sm8750/android_kernel_samsung_sm8750
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tcp: Remove TCPCT

Browse Source 
TCPCT uses option-number 253, reserved for experimental use and should
not be used in production environments.
Further, TCPCT does not fully implement RFC 6013.

As a nice side-effect, removing TCPCT increases TCP's performance for
very short flows:

Doing an apache-benchmark with -c 100 -n 100000, sending HTTP-requests
for files of 1KB size.

before this patch:
	average (among 7 runs) of 20845.5 Requests/Second
after:
	average (among 7 runs) of 21403.6 Requests/Second

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Christoph Paasch
2013-03-17 08:23:34 +00:00
committed by David S. Miller
parent 94d8f2b133
commit 1a2c6181c4
18 changed files with 37 additions and 840 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
net/ipv6/tcp_ipv6.c
View File

@@ -454,7 +454,6 @@ out:
static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
struct flowi6 *fl6,
struct request_sock *req,
struct request_values *rvp,
u16 queue_mapping)
{
struct inet6_request_sock *treq = inet6_rsk(req);
@@ -466,7 +465,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
goto done;
skb = tcp_make_synack(sk, dst, req, rvp, NULL);
skb = tcp_make_synack(sk, dst, req, NULL);
if (skb) {
__tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
@@ -481,13 +480,12 @@ done:
return err;
}
static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
struct request_values *rvp)
static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req)
{
struct flowi6 fl6;
int res;
res = tcp_v6_send_synack(sk, NULL, &fl6, req, rvp, 0);
res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0);
if (!res)
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
return res;
@@ -940,9 +938,7 @@ static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
*/
static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
{
struct tcp_extend_values tmp_ext;
struct tcp_options_received tmp_opt;
const u8 *hash_location;
struct request_sock *req;
struct inet6_request_sock *treq;
struct ipv6_pinfo *np = inet6_sk(sk);
@@ -980,50 +976,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
tcp_clear_options(&tmp_opt);
tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
tmp_opt.user_mss = tp->rx_opt.user_mss;
tcp_parse_options(skb, &tmp_opt, &hash_location, 0, NULL);
if (tmp_opt.cookie_plus > 0 &&
tmp_opt.saw_tstamp &&
!tp->rx_opt.cookie_out_never &&
(sysctl_tcp_cookie_size > 0 ||
(tp->cookie_values != NULL &&
tp->cookie_values->cookie_desired > 0))) {
u8 *c;
u32 *d;
u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
goto drop_and_free;
/* Secret recipe starts with IP addresses */
d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
*mess++ ^= *d++;
*mess++ ^= *d++;
*mess++ ^= *d++;
*mess++ ^= *d++;
d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
*mess++ ^= *d++;
*mess++ ^= *d++;
*mess++ ^= *d++;
*mess++ ^= *d++;
/* plus variable length Initiator Cookie */
c = (u8 *)mess;
while (l-- > 0)
*c++ ^= *hash_location++;
want_cookie = false; /* not our kind of cookie */
tmp_ext.cookie_out_never = 0; /* false */
tmp_ext.cookie_plus = tmp_opt.cookie_plus;
} else if (!tp->rx_opt.cookie_in_always) {
/* redundant indications, but ensure initialization. */
tmp_ext.cookie_out_never = 1; /* true */
tmp_ext.cookie_plus = 0;
} else {
goto drop_and_free;
}
tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
tcp_parse_options(skb, &tmp_opt, 0, NULL);
if (want_cookie && !tmp_opt.saw_tstamp)
tcp_clear_options(&tmp_opt);
@@ -1101,7 +1054,6 @@ have_isn:
goto drop_and_release;
if (tcp_v6_send_synack(sk, dst, &fl6, req,
(struct request_values *)&tmp_ext,
skb_get_queue_mapping(skb)) ||
want_cookie)
goto drop_and_free;