From 7586eceb0abc0ea1c2b023e3e5d4dfd4ff40930a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 20 Jun 2012 05:02:19 +0000 Subject: [PATCH] ipv4: tcp: dont cache output dst for syncookies Don't cache output dst for syncookies, as this adds pressure on IP route cache and rcu subsystem for no gain. Signed-off-by: Eric Dumazet Cc: Hans Schillstrom Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- include/net/flow.h | 1 + include/net/inet_connection_sock.h | 3 ++- net/dccp/ipv4.c | 2 +- net/ipv4/inet_connection_sock.c | 8 ++++++-- net/ipv4/route.c | 5 ++++- net/ipv4/tcp_ipv4.c | 12 +++++++----- 6 files changed, 21 insertions(+), 10 deletions(-) diff --git a/include/net/flow.h b/include/net/flow.h index 6c469dbdb917..bd524f598561 100644 --- a/include/net/flow.h +++ b/include/net/flow.h @@ -22,6 +22,7 @@ struct flowi_common { #define FLOWI_FLAG_ANYSRC 0x01 #define FLOWI_FLAG_PRECOW_METRICS 0x02 #define FLOWI_FLAG_CAN_SLEEP 0x04 +#define FLOWI_FLAG_RT_NOCACHE 0x08 __u32 flowic_secid; }; diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index e1b7734c456f..af3c743a40e4 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -251,7 +251,8 @@ extern int inet_csk_get_port(struct sock *sk, unsigned short snum); extern struct dst_entry* inet_csk_route_req(struct sock *sk, struct flowi4 *fl4, - const struct request_sock *req); + const struct request_sock *req, + bool nocache); extern struct dst_entry* inet_csk_route_child_sock(struct sock *sk, struct sock *newsk, const struct request_sock *req); diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 07f5579ca756..3eb76b5f221a 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -504,7 +504,7 @@ static int dccp_v4_send_response(struct sock *sk, struct request_sock *req, struct dst_entry *dst; struct flowi4 fl4; - dst = inet_csk_route_req(sk, &fl4, req); + dst = inet_csk_route_req(sk, &fl4, req, false); if (dst == NULL) goto out; diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index f9ee7417f6a0..034ddbe42adf 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -368,17 +368,21 @@ EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4, - const struct request_sock *req) + const struct request_sock *req, + bool nocache) { struct rtable *rt; const struct inet_request_sock *ireq = inet_rsk(req); struct ip_options_rcu *opt = inet_rsk(req)->opt; struct net *net = sock_net(sk); + int flags = inet_sk_flowi_flags(sk) & ~FLOWI_FLAG_PRECOW_METRICS; + if (nocache) + flags |= FLOWI_FLAG_RT_NOCACHE; flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, sk->sk_protocol, - inet_sk_flowi_flags(sk) & ~FLOWI_FLAG_PRECOW_METRICS, + flags, (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); security_req_classify_flow(req, flowi4_to_flowi(fl4)); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a91f6d33804c..8d62d85e68dc 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1156,7 +1156,7 @@ restart: candp = NULL; now = jiffies; - if (!rt_caching(dev_net(rt->dst.dev))) { + if (!rt_caching(dev_net(rt->dst.dev)) || (rt->dst.flags & DST_NOCACHE)) { /* * If we're not caching, just tell the caller we * were successful and don't touch the route. The @@ -2582,6 +2582,9 @@ static struct rtable *__mkroute_output(const struct fib_result *res, rt_set_nexthop(rth, fl4, res, fi, type, 0); + if (fl4->flowi4_flags & FLOWI_FLAG_RT_NOCACHE) + rth->dst.flags |= DST_NOCACHE; + return rth; } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 21e22a00481a..b52934f5334e 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -825,7 +825,8 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, struct request_sock *req, struct request_values *rvp, - u16 queue_mapping) + u16 queue_mapping, + bool nocache) { const struct inet_request_sock *ireq = inet_rsk(req); struct flowi4 fl4; @@ -833,7 +834,7 @@ static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, struct sk_buff * skb; /* First, grab a route. */ - if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) + if (!dst && (dst = inet_csk_route_req(sk, &fl4, req, nocache)) == NULL) return -1; skb = tcp_make_synack(sk, dst, req, rvp); @@ -855,7 +856,7 @@ static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req, struct request_values *rvp) { TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); - return tcp_v4_send_synack(sk, NULL, req, rvp, 0); + return tcp_v4_send_synack(sk, NULL, req, rvp, 0, false); } /* @@ -1388,7 +1389,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) */ if (tmp_opt.saw_tstamp && tcp_death_row.sysctl_tw_recycle && - (dst = inet_csk_route_req(sk, &fl4, req)) != NULL && + (dst = inet_csk_route_req(sk, &fl4, req, want_cookie)) != NULL && fl4.daddr == saddr && (peer = rt_get_peer((struct rtable *)dst, fl4.daddr)) != NULL) { inet_peer_refcheck(peer); @@ -1424,7 +1425,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) if (tcp_v4_send_synack(sk, dst, req, (struct request_values *)&tmp_ext, - skb_get_queue_mapping(skb)) || + skb_get_queue_mapping(skb), + want_cookie) || want_cookie) goto drop_and_free;