tcp: Add timewait recycling bits to ipv6 connect code. (493f377d) · Commits · 戴 / test

net/core/request_sock.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@
		* Note : Dont forget somaxconn that may limit backlog too.
		*/
		int sysctl_max_syn_backlog = 256;
		EXPORT_SYMBOL(sysctl_max_syn_backlog);

		int reqsk_queue_alloc(struct request_sock_queue *queue,
		unsigned int nr_table_entries)

net/ipv6/tcp_ipv6.c

+76 −25

Original line number	Diff line number	Diff line
		@@ -130,6 +130,7 @@ static int tcp_v6_connect(struct sock sk, struct sockaddr uaddr,
		struct ipv6_pinfo *np = inet6_sk(sk);
		struct tcp_sock *tp = tcp_sk(sk);
		struct in6_addr saddr = NULL, final_p, final;
		struct rt6_info *rt;
		struct flowi fl;
		struct dst_entry *dst;
		int addr_type;
		@@ -280,6 +281,26 @@ static int tcp_v6_connect(struct sock sk, struct sockaddr uaddr,
		sk->sk_gso_type = SKB_GSO_TCPV6;
		__ip6_dst_store(sk, dst, NULL, NULL);

		rt = (struct rt6_info *) dst;
		if (tcp_death_row.sysctl_tw_recycle &&
		!tp->rx_opt.ts_recent_stamp &&
		ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
		struct inet_peer *peer = rt6_get_peer(rt);
		/*
		* VJ's idea. We save last timestamp seen from
		* the destination in peer table, when entering state
		* TIME-WAIT * and initialize rx_opt.ts_recent from it,
		* when trying new connection.
		*/
		if (peer) {
		inet_peer_refcheck(peer);
		if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
		tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
		tp->rx_opt.ts_recent = peer->tcp_ts;
		}
		}
		}

		icsk->icsk_ext_hdr_len = 0;
		if (np->opt)
		icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
		@@ -1170,6 +1191,7 @@ static int tcp_v6_conn_request(struct sock sk, struct sk_buff skb)
		struct ipv6_pinfo *np = inet6_sk(sk);
		struct tcp_sock *tp = tcp_sk(sk);
		__u32 isn = TCP_SKB_CB(skb)->when;
		struct dst_entry *dst = NULL;
		#ifdef CONFIG_SYN_COOKIES
		int want_cookie = 0;
		#else
		@@ -1267,6 +1289,8 @@ static int tcp_v6_conn_request(struct sock sk, struct sk_buff skb)
		TCP_ECN_create_request(req, tcp_hdr(skb));

		if (!isn) {
		struct inet_peer *peer = NULL;

		if (ipv6_opt_accepted(sk, skb) \|\|
		np->rxopt.bits.rxinfo \|\| np->rxopt.bits.rxoinfo \|\|
		np->rxopt.bits.rxhlim \|\| np->rxopt.bits.rxohlim) {
		@@ -1279,13 +1303,57 @@ static int tcp_v6_conn_request(struct sock sk, struct sk_buff skb)
		if (!sk->sk_bound_dev_if &&
		ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
		treq->iif = inet6_iif(skb);
		if (!want_cookie) {
		isn = tcp_v6_init_sequence(skb);
		} else {

		if (want_cookie) {
		isn = cookie_v6_init_sequence(sk, skb, &req->mss);
		req->cookie_ts = tmp_opt.tstamp_ok;
		goto have_isn;
		}

		/* VJ's idea. We save last timestamp seen
		* from the destination in peer table, when entering
		* state TIME-WAIT, and check against it before
		* accepting new connection request.
		*
		* If "isn" is not zero, this request hit alive
		* timewait bucket, so that all the necessary checks
		* are made in the function processing timewait state.
		*/
		if (tmp_opt.saw_tstamp &&
		tcp_death_row.sysctl_tw_recycle &&
		(dst = inet6_csk_route_req(sk, req)) != NULL &&
		(peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
		ipv6_addr_equal((struct in6_addr *)peer->daddr.a6,
		&treq->rmt_addr)) {
		inet_peer_refcheck(peer);
		if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
		(s32)(peer->tcp_ts - req->ts_recent) >
		TCP_PAWS_WINDOW) {
		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
		goto drop_and_release;
		}
		}
		/* Kill the following clause, if you dislike this way. */
		else if (!sysctl_tcp_syncookies &&
		(sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
		(sysctl_max_syn_backlog >> 2)) &&
		(!peer \|\| !peer->tcp_ts_stamp) &&
		(!dst \|\| !dst_metric(dst, RTAX_RTT))) {
		/* Without syncookies last quarter of
		* backlog is filled with destinations,
		* proven to be alive.
		* It means that we continue to communicate
		* to destinations, already remembered
		* to the moment of synflood.
		*/
		LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
		&treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
		goto drop_and_release;
		}

		isn = tcp_v6_init_sequence(skb);
		}
		have_isn:
		tcp_rsk(req)->snt_isn = isn;

		security_inet_conn_request(sk, skb, req);
		@@ -1298,6 +1366,8 @@ static int tcp_v6_conn_request(struct sock sk, struct sk_buff skb)
		inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
		return 0;

		drop_and_release:
		dst_release(dst);
		drop_and_free:
		reqsk_free(req);
		drop:
		@@ -1376,28 +1446,9 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock sk, struct sk_buff skb,
		if (sk_acceptq_is_full(sk))
		goto out_overflow;

		if (dst == NULL) {
		struct in6_addr *final_p, final;
		struct flowi fl;

		memset(&fl, 0, sizeof(fl));
		fl.proto = IPPROTO_TCP;
		ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
		final_p = fl6_update_dst(&fl, opt, &final);
		ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
		fl.oif = sk->sk_bound_dev_if;
		fl.mark = sk->sk_mark;
		fl.fl_ip_dport = inet_rsk(req)->rmt_port;
		fl.fl_ip_sport = inet_rsk(req)->loc_port;
		security_req_classify_flow(req, &fl);

		if (ip6_dst_lookup(sk, &dst, &fl))
		goto out;

		if (final_p)
		ipv6_addr_copy(&fl.fl6_dst, final_p);

		if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
		if (!dst) {
		dst = inet6_csk_route_req(sk, req);
		if (!dst)
		goto out;
		}

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