diff options
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 645 |
1 files changed, 416 insertions, 229 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 2fbd9921253f..b14266bb91eb 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -75,6 +75,7 @@ #include <net/netdma.h> #include <net/secure_seq.h> #include <net/tcp_memcontrol.h> +#include <net/busy_poll.h> #include <linux/inet.h> #include <linux/ipv6.h> @@ -138,14 +139,6 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) } EXPORT_SYMBOL_GPL(tcp_twsk_unique); -static int tcp_repair_connect(struct sock *sk) -{ - tcp_connect_init(sk); - tcp_finish_connect(sk, NULL); - - return 0; -} - /* This will initiate an outgoing connection. */ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { @@ -250,10 +243,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) inet->inet_id = tp->write_seq ^ jiffies; - if (likely(!tp->repair)) - err = tcp_connect(sk); - else - err = tcp_repair_connect(sk); + err = tcp_connect(sk); rt = NULL; if (err) @@ -285,13 +275,6 @@ static void tcp_v4_mtu_reduced(struct sock *sk) struct inet_sock *inet = inet_sk(sk); u32 mtu = tcp_sk(sk)->mtu_info; - /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs - * send out by Linux are always <576bytes so they should go through - * unfragmented). - */ - if (sk->sk_state == TCP_LISTEN) - return; - dst = inet_csk_update_pmtu(sk, mtu); if (!dst) return; @@ -352,6 +335,7 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) const int code = icmp_hdr(icmp_skb)->code; struct sock *sk; struct sk_buff *skb; + struct request_sock *req; __u32 seq; __u32 remaining; int err; @@ -379,11 +363,10 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) * We do take care of PMTU discovery (RFC1191) special case : * we can receive locally generated ICMP messages while socket is held. */ - if (sock_owned_by_user(sk) && - type != ICMP_DEST_UNREACH && - code != ICMP_FRAG_NEEDED) - NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); - + if (sock_owned_by_user(sk)) { + if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)) + NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); + } if (sk->sk_state == TCP_CLOSE) goto out; @@ -394,9 +377,12 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) icsk = inet_csk(sk); tp = tcp_sk(sk); + req = tp->fastopen_rsk; seq = ntohl(th->seq); if (sk->sk_state != TCP_LISTEN && - !between(seq, tp->snd_una, tp->snd_nxt)) { + !between(seq, tp->snd_una, tp->snd_nxt) && + (req == NULL || seq != tcp_rsk(req)->snt_isn)) { + /* For a Fast Open socket, allow seq to be snt_isn. */ NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); goto out; } @@ -416,11 +402,20 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) goto out; if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ + /* We are not interested in TCP_LISTEN and open_requests + * (SYN-ACKs send out by Linux are always <576bytes so + * they should go through unfragmented). + */ + if (sk->sk_state == TCP_LISTEN) + goto out; + tp->mtu_info = info; - if (!sock_owned_by_user(sk)) + if (!sock_owned_by_user(sk)) { tcp_v4_mtu_reduced(sk); - else - set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags); + } else { + if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags)) + sock_hold(sk); + } goto out; } @@ -433,6 +428,8 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) !icsk->icsk_backoff) break; + /* XXX (TFO) - revisit the following logic for TFO */ + if (sock_owned_by_user(sk)) break; @@ -464,6 +461,14 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) goto out; } + /* XXX (TFO) - if it's a TFO socket and has been accepted, rather + * than following the TCP_SYN_RECV case and closing the socket, + * we ignore the ICMP error and keep trying like a fully established + * socket. Is this the right thing to do? + */ + if (req && req->sk == NULL) + goto out; + switch (sk->sk_state) { struct request_sock *req, **prev; case TCP_LISTEN: @@ -492,11 +497,13 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) * errors returned from accept(). */ inet_csk_reqsk_queue_drop(sk, req, prev); + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); goto out; case TCP_SYN_SENT: case TCP_SYN_RECV: /* Cannot happen. - It can f.e. if SYNs crossed. + It can f.e. if SYNs crossed, + or Fast Open. */ if (!sock_owned_by_user(sk)) { sk->sk_err = err; @@ -539,8 +546,7 @@ out: sock_put(sk); } -static void __tcp_v4_send_check(struct sk_buff *skb, - __be32 saddr, __be32 daddr) +void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) { struct tcphdr *th = tcp_hdr(skb); @@ -565,23 +571,6 @@ void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) } EXPORT_SYMBOL(tcp_v4_send_check); -int tcp_v4_gso_send_check(struct sk_buff *skb) -{ - const struct iphdr *iph; - struct tcphdr *th; - - if (!pskb_may_pull(skb, sizeof(*th))) - return -EINVAL; - - iph = ip_hdr(skb); - th = tcp_hdr(skb); - - th->check = 0; - skb->ip_summed = CHECKSUM_PARTIAL; - __tcp_v4_send_check(skb, iph->saddr, iph->daddr); - return 0; -} - /* * This routine will send an RST to the other tcp. * @@ -651,7 +640,8 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) * no RST generated if md5 hash doesn't match. */ sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev), - &tcp_hashinfo, ip_hdr(skb)->daddr, + &tcp_hashinfo, ip_hdr(skb)->saddr, + th->source, ip_hdr(skb)->daddr, ntohs(th->source), inet_iif(skb)); /* don't send rst if it can't find key */ if (!sk1) @@ -691,10 +681,11 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) arg.csumoffset = offsetof(struct tcphdr, check) / 2; arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0; /* When socket is gone, all binding information is lost. - * routing might fail in this case. using iif for oif to - * make sure we can deliver it + * routing might fail in this case. No choice here, if we choose to force + * input interface, we will misroute in case of asymmetric route. */ - arg.bound_dev_if = sk ? sk->sk_bound_dev_if : inet_iif(skb); + if (sk) + arg.bound_dev_if = sk->sk_bound_dev_if; net = dev_net(skb_dst(skb)->dev); arg.tos = ip_hdr(skb)->tos; @@ -718,7 +709,7 @@ release_sk1: */ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, - u32 win, u32 ts, int oif, + u32 win, u32 tsval, u32 tsecr, int oif, struct tcp_md5sig_key *key, int reply_flags, u8 tos) { @@ -739,12 +730,12 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, arg.iov[0].iov_base = (unsigned char *)&rep; arg.iov[0].iov_len = sizeof(rep.th); - if (ts) { + if (tsecr) { rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); - rep.opt[1] = htonl(tcp_time_stamp); - rep.opt[2] = htonl(ts); + rep.opt[1] = htonl(tsval); + rep.opt[2] = htonl(tsecr); arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; } @@ -759,7 +750,7 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, #ifdef CONFIG_TCP_MD5SIG if (key) { - int offset = (ts) ? 3 : 0; + int offset = (tsecr) ? 3 : 0; rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | @@ -794,6 +785,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, + tcp_time_stamp + tcptw->tw_ts_offset, tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw), @@ -807,8 +799,13 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, - tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, + /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV + * sk->sk_state == TCP_SYN_RECV -> for Fast Open. + */ + tcp_v4_send_ack(skb, (sk->sk_state == TCP_LISTEN) ? + tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, + tcp_rsk(req)->rcv_nxt, req->rcv_wnd, + tcp_time_stamp, req->ts_recent, 0, tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr, @@ -824,9 +821,7 @@ 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, - bool nocache) + u16 queue_mapping) { const struct inet_request_sock *ireq = inet_rsk(req); struct flowi4 fl4; @@ -837,7 +832,7 @@ static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) return -1; - skb = tcp_make_synack(sk, dst, req, rvp); + skb = tcp_make_synack(sk, dst, req, NULL); if (skb) { __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr); @@ -847,16 +842,20 @@ static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, ireq->rmt_addr, ireq->opt); err = net_xmit_eval(err); + if (!tcp_rsk(req)->snt_synack && !err) + tcp_rsk(req)->snt_synack = tcp_time_stamp; } return err; } -static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req, - struct request_values *rvp) +static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req) { - TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); - return tcp_v4_send_synack(sk, NULL, req, rvp, 0, false); + int res = tcp_v4_send_synack(sk, NULL, req, 0); + + if (!res) + TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); + return res; } /* @@ -890,7 +889,7 @@ bool tcp_syn_flood_action(struct sock *sk, NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP); lopt = inet_csk(sk)->icsk_accept_queue.listen_opt; - if (!lopt->synflood_warned) { + if (!lopt->synflood_warned && sysctl_tcp_syncookies != 2) { lopt->synflood_warned = 1; pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n", proto, ntohs(tcp_hdr(skb)->dest), msg); @@ -902,8 +901,7 @@ EXPORT_SYMBOL(tcp_syn_flood_action); /* * Save and compile IPv4 options into the request_sock if needed. */ -static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk, - struct sk_buff *skb) +static struct ip_options_rcu *tcp_v4_save_options(struct sk_buff *skb) { const struct ip_options *opt = &(IPCB(skb)->opt); struct ip_options_rcu *dopt = NULL; @@ -936,7 +934,6 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, { struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; - struct hlist_node *pos; unsigned int size = sizeof(struct in_addr); struct tcp_md5sig_info *md5sig; @@ -950,7 +947,7 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, if (family == AF_INET6) size = sizeof(struct in6_addr); #endif - hlist_for_each_entry_rcu(key, pos, &md5sig->head, node) { + hlist_for_each_entry_rcu(key, &md5sig->head, node) { if (key->family != family) continue; if (!memcmp(&key->addr, addr, size)) @@ -988,7 +985,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_info *md5sig; - key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET); + key = tcp_md5_do_lookup(sk, addr, family); if (key) { /* Pre-existing entry - just update that one. */ memcpy(key->key, newkey, newkeylen); @@ -1011,7 +1008,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, key = sock_kmalloc(sk, sizeof(*key), gfp); if (!key) return -ENOMEM; - if (hlist_empty(&md5sig->head) && !tcp_alloc_md5sig_pool(sk)) { + if (!tcp_alloc_md5sig_pool()) { sock_kfree_s(sk, key, sizeof(*key)); return -ENOMEM; } @@ -1029,36 +1026,28 @@ EXPORT_SYMBOL(tcp_md5_do_add); int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family) { - struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; - struct tcp_md5sig_info *md5sig; - key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET); + key = tcp_md5_do_lookup(sk, addr, family); if (!key) return -ENOENT; hlist_del_rcu(&key->node); atomic_sub(sizeof(*key), &sk->sk_omem_alloc); kfree_rcu(key, rcu); - md5sig = rcu_dereference_protected(tp->md5sig_info, - sock_owned_by_user(sk)); - if (hlist_empty(&md5sig->head)) - tcp_free_md5sig_pool(); return 0; } EXPORT_SYMBOL(tcp_md5_do_del); -void tcp_clear_md5_list(struct sock *sk) +static void tcp_clear_md5_list(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; - struct hlist_node *pos, *n; + struct hlist_node *n; struct tcp_md5sig_info *md5sig; md5sig = rcu_dereference_protected(tp->md5sig_info, 1); - if (!hlist_empty(&md5sig->head)) - tcp_free_md5sig_pool(); - hlist_for_each_entry_safe(key, pos, n, &md5sig->head, node) { + hlist_for_each_entry_safe(key, n, &md5sig->head, node) { hlist_del_rcu(&key->node); atomic_sub(sizeof(*key), &sk->sk_omem_alloc); kfree_rcu(key, rcu); @@ -1270,11 +1259,190 @@ static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { }; #endif +static bool tcp_fastopen_check(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + struct tcp_fastopen_cookie *valid_foc) +{ + bool skip_cookie = false; + struct fastopen_queue *fastopenq; + + if (likely(!fastopen_cookie_present(foc))) { + /* See include/net/tcp.h for the meaning of these knobs */ + if ((sysctl_tcp_fastopen & TFO_SERVER_ALWAYS) || + ((sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD) && + (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1))) + skip_cookie = true; /* no cookie to validate */ + else + return false; + } + fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq; + /* A FO option is present; bump the counter. */ + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVE); + + /* Make sure the listener has enabled fastopen, and we don't + * exceed the max # of pending TFO requests allowed before trying + * to validating the cookie in order to avoid burning CPU cycles + * unnecessarily. + * + * XXX (TFO) - The implication of checking the max_qlen before + * processing a cookie request is that clients can't differentiate + * between qlen overflow causing Fast Open to be disabled + * temporarily vs a server not supporting Fast Open at all. + */ + if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) == 0 || + fastopenq == NULL || fastopenq->max_qlen == 0) + return false; + + if (fastopenq->qlen >= fastopenq->max_qlen) { + struct request_sock *req1; + spin_lock(&fastopenq->lock); + req1 = fastopenq->rskq_rst_head; + if ((req1 == NULL) || time_after(req1->expires, jiffies)) { + spin_unlock(&fastopenq->lock); + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPFASTOPENLISTENOVERFLOW); + /* Avoid bumping LINUX_MIB_TCPFASTOPENPASSIVEFAIL*/ + foc->len = -1; + return false; + } + fastopenq->rskq_rst_head = req1->dl_next; + fastopenq->qlen--; + spin_unlock(&fastopenq->lock); + reqsk_free(req1); + } + if (skip_cookie) { + tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->end_seq; + return true; + } + + if (foc->len == TCP_FASTOPEN_COOKIE_SIZE) { + if ((sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_CHKED) == 0) { + tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, valid_foc); + if ((valid_foc->len != TCP_FASTOPEN_COOKIE_SIZE) || + memcmp(&foc->val[0], &valid_foc->val[0], + TCP_FASTOPEN_COOKIE_SIZE) != 0) + return false; + valid_foc->len = -1; + } + /* Acknowledge the data received from the peer. */ + tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->end_seq; + return true; + } else if (foc->len == 0) { /* Client requesting a cookie */ + tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, valid_foc); + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPFASTOPENCOOKIEREQD); + } else { + /* Client sent a cookie with wrong size. Treat it + * the same as invalid and return a valid one. + */ + tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, valid_foc); + } + return false; +} + +static int tcp_v4_conn_req_fastopen(struct sock *sk, + struct sk_buff *skb, + struct sk_buff *skb_synack, + struct request_sock *req) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; + const struct inet_request_sock *ireq = inet_rsk(req); + struct sock *child; + int err; + + req->num_retrans = 0; + req->num_timeout = 0; + req->sk = NULL; + + child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL); + if (child == NULL) { + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVEFAIL); + kfree_skb(skb_synack); + return -1; + } + err = ip_build_and_send_pkt(skb_synack, sk, ireq->loc_addr, + ireq->rmt_addr, ireq->opt); + err = net_xmit_eval(err); + if (!err) + tcp_rsk(req)->snt_synack = tcp_time_stamp; + /* XXX (TFO) - is it ok to ignore error and continue? */ + + spin_lock(&queue->fastopenq->lock); + queue->fastopenq->qlen++; + spin_unlock(&queue->fastopenq->lock); + + /* Initialize the child socket. Have to fix some values to take + * into account the child is a Fast Open socket and is created + * only out of the bits carried in the SYN packet. + */ + tp = tcp_sk(child); + + tp->fastopen_rsk = req; + /* Do a hold on the listner sk so that if the listener is being + * closed, the child that has been accepted can live on and still + * access listen_lock. + */ + sock_hold(sk); + tcp_rsk(req)->listener = sk; + + /* RFC1323: The window in SYN & SYN/ACK segments is never + * scaled. So correct it appropriately. + */ + tp->snd_wnd = ntohs(tcp_hdr(skb)->window); + + /* Activate the retrans timer so that SYNACK can be retransmitted. + * The request socket is not added to the SYN table of the parent + * because it's been added to the accept queue directly. + */ + inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS, + TCP_TIMEOUT_INIT, TCP_RTO_MAX); + + /* Add the child socket directly into the accept queue */ + inet_csk_reqsk_queue_add(sk, req, child); + + /* Now finish processing the fastopen child socket. */ + inet_csk(child)->icsk_af_ops->rebuild_header(child); + tcp_init_congestion_control(child); + tcp_mtup_init(child); + tcp_init_buffer_space(child); + tcp_init_metrics(child); + + /* Queue the data carried in the SYN packet. We need to first + * bump skb's refcnt because the caller will attempt to free it. + * + * XXX (TFO) - we honor a zero-payload TFO request for now. + * (Any reason not to?) + */ + if (TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq + 1) { + /* Don't queue the skb if there is no payload in SYN. + * XXX (TFO) - How about SYN+FIN? + */ + tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq; + } else { + skb = skb_get(skb); + skb_dst_drop(skb); + __skb_pull(skb, tcp_hdr(skb)->doff * 4); + skb_set_owner_r(skb, child); + __skb_queue_tail(&child->sk_receive_queue, skb); + tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq; + tp->syn_data_acked = 1; + } + sk->sk_data_ready(sk, 0); + bh_unlock_sock(child); + sock_put(child); + WARN_ON(req->sk == NULL); + return 0; +} + int tcp_v4_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 inet_request_sock *ireq; struct tcp_sock *tp = tcp_sk(sk); @@ -1283,6 +1451,11 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) __be32 daddr = ip_hdr(skb)->daddr; __u32 isn = TCP_SKB_CB(skb)->when; bool want_cookie = false; + struct flowi4 fl4; + struct tcp_fastopen_cookie foc = { .len = -1 }; + struct tcp_fastopen_cookie valid_foc = { .len = -1 }; + struct sk_buff *skb_synack; + int do_fastopen; /* Never answer to SYNs send to broadcast or multicast */ if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) @@ -1292,7 +1465,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) * limitations, they conserve resources and peer is * evidently real one. */ - if (inet_csk_reqsk_queue_is_full(sk) && !isn) { + if ((sysctl_tcp_syncookies == 2 || + inet_csk_reqsk_queue_is_full(sk)) && !isn) { want_cookie = tcp_syn_flood_action(sk, skb, "TCP"); if (!want_cookie) goto drop; @@ -1303,8 +1477,10 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) * clogging syn queue with openreqs with exponentially increasing * timeout. */ - if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) + if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) { + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); goto drop; + } req = inet_reqsk_alloc(&tcp_request_sock_ops); if (!req) @@ -1317,41 +1493,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) tcp_clear_options(&tmp_opt); tmp_opt.mss_clamp = TCP_MSS_DEFAULT; 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 *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_release; - - /* Secret recipe starts with IP addresses */ - *mess++ ^= (__force u32)daddr; - *mess++ ^= (__force u32)saddr; - - /* 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_release; - } - tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always; + tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc); if (want_cookie && !tmp_opt.saw_tstamp) tcp_clear_options(&tmp_opt); @@ -1363,20 +1505,18 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) ireq->loc_addr = daddr; ireq->rmt_addr = saddr; ireq->no_srccheck = inet_sk(sk)->transparent; - ireq->opt = tcp_v4_save_options(sk, skb); + ireq->opt = tcp_v4_save_options(skb); if (security_inet_conn_request(sk, skb, req)) goto drop_and_free; if (!want_cookie || tmp_opt.tstamp_ok) - TCP_ECN_create_request(req, skb); + TCP_ECN_create_request(req, skb, sock_net(sk)); if (want_cookie) { isn = cookie_v4_init_sequence(sk, skb, &req->mss); req->cookie_ts = tmp_opt.tstamp_ok; } else if (!isn) { - struct flowi4 fl4; - /* VJ's idea. We save last timestamp seen * from the destination in peer table, when entering * state TIME-WAIT, and check against it before @@ -1415,16 +1555,52 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) isn = tcp_v4_init_sequence(skb); } tcp_rsk(req)->snt_isn = isn; - tcp_rsk(req)->snt_synack = tcp_time_stamp; - if (tcp_v4_send_synack(sk, dst, req, - (struct request_values *)&tmp_ext, - skb_get_queue_mapping(skb), - want_cookie) || - want_cookie) + if (dst == NULL) { + dst = inet_csk_route_req(sk, &fl4, req); + if (dst == NULL) + goto drop_and_free; + } + do_fastopen = tcp_fastopen_check(sk, skb, req, &foc, &valid_foc); + + /* We don't call tcp_v4_send_synack() directly because we need + * to make sure a child socket can be created successfully before + * sending back synack! + * + * XXX (TFO) - Ideally one would simply call tcp_v4_send_synack() + * (or better yet, call tcp_send_synack() in the child context + * directly, but will have to fix bunch of other code first) + * after syn_recv_sock() except one will need to first fix the + * latter to remove its dependency on the current implementation + * of tcp_v4_send_synack()->tcp_select_initial_window(). + */ + skb_synack = tcp_make_synack(sk, dst, req, + fastopen_cookie_present(&valid_foc) ? &valid_foc : NULL); + + if (skb_synack) { + __tcp_v4_send_check(skb_synack, ireq->loc_addr, ireq->rmt_addr); + skb_set_queue_mapping(skb_synack, skb_get_queue_mapping(skb)); + } else + goto drop_and_free; + + if (likely(!do_fastopen)) { + int err; + err = ip_build_and_send_pkt(skb_synack, sk, ireq->loc_addr, + ireq->rmt_addr, ireq->opt); + err = net_xmit_eval(err); + if (err || want_cookie) + goto drop_and_free; + + tcp_rsk(req)->snt_synack = tcp_time_stamp; + tcp_rsk(req)->listener = NULL; + /* Add the request_sock to the SYN table */ + inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); + if (fastopen_cookie_present(&foc) && foc.len != 0) + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVEFAIL); + } else if (tcp_v4_conn_req_fastopen(sk, skb, skb_synack, req)) goto drop_and_free; - inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); return 0; drop_and_release: @@ -1432,6 +1608,7 @@ drop_and_release: drop_and_free: reqsk_free(req); drop: + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); return 0; } EXPORT_SYMBOL(tcp_v4_conn_request); @@ -1462,6 +1639,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, goto exit_nonewsk; newsk->sk_gso_type = SKB_GSO_TCPV4; + inet_sk_rx_dst_set(newsk, skb); newtp = tcp_sk(newsk); newinet = inet_sk(newsk); @@ -1497,10 +1675,6 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; tcp_initialize_rcv_mss(newsk); - if (tcp_rsk(req)->snt_synack) - tcp_valid_rtt_meas(newsk, - tcp_time_stamp - tcp_rsk(req)->snt_synack); - newtp->total_retrans = req->retrans; #ifdef CONFIG_TCP_MD5SIG /* Copy over the MD5 key from the original socket */ @@ -1533,10 +1707,8 @@ exit: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); return NULL; put_and_exit: - tcp_clear_xmit_timers(newsk); - tcp_cleanup_congestion_control(newsk); - bh_unlock_sock(newsk); - sock_put(newsk); + inet_csk_prepare_forced_close(newsk); + tcp_done(newsk); goto exit; } EXPORT_SYMBOL(tcp_v4_syn_recv_sock); @@ -1551,7 +1723,7 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) struct request_sock *req = inet_csk_search_req(sk, &prev, th->source, iph->saddr, iph->daddr); if (req) - return tcp_check_req(sk, skb, req, prev); + return tcp_check_req(sk, skb, req, prev, false); nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr, th->source, iph->daddr, th->dest, inet_iif(skb)); @@ -1617,23 +1789,17 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) #endif if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ + struct dst_entry *dst = sk->sk_rx_dst; + sock_rps_save_rxhash(sk, skb); - if (sk->sk_rx_dst) { - struct dst_entry *dst = sk->sk_rx_dst; + if (dst) { if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif || dst->ops->check(dst, 0) == NULL) { dst_release(dst); sk->sk_rx_dst = NULL; } } - if (unlikely(sk->sk_rx_dst == NULL)) { - sk->sk_rx_dst = dst_clone(skb_dst(skb)); - inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; - } - if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) { - rsk = sk; - goto reset; - } + tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len); return 0; } @@ -1674,6 +1840,7 @@ discard: return 0; csum_err: + TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS); TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); goto discard; } @@ -1681,7 +1848,6 @@ EXPORT_SYMBOL(tcp_v4_do_rcv); void tcp_v4_early_demux(struct sk_buff *skb) { - struct net *net = dev_net(skb->dev); const struct iphdr *iph; const struct tcphdr *th; struct sock *sk; @@ -1689,16 +1855,16 @@ void tcp_v4_early_demux(struct sk_buff *skb) if (skb->pkt_type != PACKET_HOST) return; - if (!pskb_may_pull(skb, ip_hdrlen(skb) + sizeof(struct tcphdr))) + if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) return; iph = ip_hdr(skb); - th = (struct tcphdr *) ((char *)iph + ip_hdrlen(skb)); + th = tcp_hdr(skb); if (th->doff < sizeof(struct tcphdr) / 4) return; - sk = __inet_lookup_established(net, &tcp_hashinfo, + sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, iph->saddr, th->source, iph->daddr, ntohs(th->dest), skb->skb_iif); @@ -1717,6 +1883,51 @@ void tcp_v4_early_demux(struct sk_buff *skb) } } +/* Packet is added to VJ-style prequeue for processing in process + * context, if a reader task is waiting. Apparently, this exciting + * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) + * failed somewhere. Latency? Burstiness? Well, at least now we will + * see, why it failed. 8)8) --ANK + * + */ +bool tcp_prequeue(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (sysctl_tcp_low_latency || !tp->ucopy.task) + return false; + + if (skb->len <= tcp_hdrlen(skb) && + skb_queue_len(&tp->ucopy.prequeue) == 0) + return false; + + skb_dst_force(skb); + __skb_queue_tail(&tp->ucopy.prequeue, skb); + tp->ucopy.memory += skb->truesize; + if (tp->ucopy.memory > sk->sk_rcvbuf) { + struct sk_buff *skb1; + + BUG_ON(sock_owned_by_user(sk)); + + while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { + sk_backlog_rcv(sk, skb1); + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPPREQUEUEDROPPED); + } + + tp->ucopy.memory = 0; + } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { + wake_up_interruptible_sync_poll(sk_sleep(sk), + POLLIN | POLLRDNORM | POLLRDBAND); + if (!inet_csk_ack_scheduled(sk)) + inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, + (3 * tcp_rto_min(sk)) / 4, + TCP_RTO_MAX); + } + return true; +} +EXPORT_SYMBOL(tcp_prequeue); + /* * From tcp_input.c */ @@ -1750,7 +1961,7 @@ int tcp_v4_rcv(struct sk_buff *skb) * provided case of th->doff==0 is eliminated. * So, we defer the checks. */ if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb)) - goto bad_packet; + goto csum_error; th = tcp_hdr(skb); iph = ip_hdr(skb); @@ -1782,6 +1993,7 @@ process: if (sk_filter(sk, skb)) goto discard_and_relse; + sk_mark_napi_id(sk, skb); skb->dev = NULL; bh_lock_sock_nested(sk); @@ -1816,6 +2028,8 @@ no_tcp_socket: goto discard_it; if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { +csum_error: + TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS); bad_packet: TCP_INC_STATS_BH(net, TCP_MIB_INERRS); } else { @@ -1837,15 +2051,19 @@ do_time_wait: goto discard_it; } - if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { - TCP_INC_STATS_BH(net, TCP_MIB_INERRS); + if (skb->len < (th->doff << 2)) { inet_twsk_put(inet_twsk(sk)); - goto discard_it; + goto bad_packet; + } + if (tcp_checksum_complete(skb)) { + inet_twsk_put(inet_twsk(sk)); + goto csum_error; } switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { case TCP_TW_SYN: { struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, + iph->saddr, th->source, iph->daddr, th->dest, inet_iif(skb)); if (sk2) { @@ -1872,10 +2090,21 @@ static struct timewait_sock_ops tcp_timewait_sock_ops = { .twsk_destructor= tcp_twsk_destructor, }; +void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + + dst_hold(dst); + sk->sk_rx_dst = dst; + inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; +} +EXPORT_SYMBOL(inet_sk_rx_dst_set); + const struct inet_connection_sock_af_ops ipv4_specific = { .queue_xmit = ip_queue_xmit, .send_check = tcp_v4_send_check, .rebuild_header = inet_sk_rebuild_header, + .sk_rx_dst_set = inet_sk_rx_dst_set, .conn_request = tcp_v4_conn_request, .syn_recv_sock = tcp_v4_syn_recv_sock, .net_header_len = sizeof(struct iphdr), @@ -1952,20 +2181,7 @@ void tcp_v4_destroy_sock(struct sock *sk) if (inet_csk(sk)->icsk_bind_hash) inet_put_port(sk); - /* - * If sendmsg cached page exists, toss it. - */ - if (sk->sk_sndmsg_page) { - __free_page(sk->sk_sndmsg_page); - sk->sk_sndmsg_page = NULL; - } - - /* TCP Cookie Transactions */ - if (tp->cookie_values != NULL) { - kref_put(&tp->cookie_values->kref, - tcp_cookie_values_release); - tp->cookie_values = NULL; - } + BUG_ON(tp->fastopen_rsk != NULL); /* If socket is aborted during connect operation */ tcp_free_fastopen_req(tp); @@ -2342,7 +2558,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v) int tcp_seq_open(struct inode *inode, struct file *file) { - struct tcp_seq_afinfo *afinfo = PDE(inode)->data; + struct tcp_seq_afinfo *afinfo = PDE_DATA(inode); struct tcp_iter_state *s; int err; @@ -2377,18 +2593,18 @@ EXPORT_SYMBOL(tcp_proc_register); void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) { - proc_net_remove(net, afinfo->name); + remove_proc_entry(afinfo->name, net->proc_net); } EXPORT_SYMBOL(tcp_proc_unregister); static void get_openreq4(const struct sock *sk, const struct request_sock *req, - struct seq_file *f, int i, int uid, int *len) + struct seq_file *f, int i, kuid_t uid, int *len) { const struct inet_request_sock *ireq = inet_rsk(req); - int ttd = req->expires - jiffies; + long delta = req->expires - jiffies; seq_printf(f, "%4d: %08X:%04X %08X:%04X" - " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n", + " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK%n", i, ireq->loc_addr, ntohs(inet_sk(sk)->inet_sport), @@ -2397,9 +2613,9 @@ static void get_openreq4(const struct sock *sk, const struct request_sock *req, TCP_SYN_RECV, 0, 0, /* could print option size, but that is af dependent. */ 1, /* timers active (only the expire timer) */ - jiffies_to_clock_t(ttd), - req->retrans, - uid, + jiffies_delta_to_clock_t(delta), + req->num_timeout, + from_kuid_munged(seq_user_ns(f), uid), 0, /* non standard timer */ 0, /* open_requests have no inode */ atomic_read(&sk->sk_refcnt), @@ -2414,13 +2630,16 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) const struct tcp_sock *tp = tcp_sk(sk); const struct inet_connection_sock *icsk = inet_csk(sk); const struct inet_sock *inet = inet_sk(sk); + struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq; __be32 dest = inet->inet_daddr; __be32 src = inet->inet_rcv_saddr; __u16 destp = ntohs(inet->inet_dport); __u16 srcp = ntohs(inet->inet_sport); int rx_queue; - if (icsk->icsk_pending == ICSK_TIME_RETRANS) { + if (icsk->icsk_pending == ICSK_TIME_RETRANS || + icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS || + icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { timer_active = 1; timer_expires = icsk->icsk_timeout; } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { @@ -2443,14 +2662,14 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " - "%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n", + "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d%n", i, src, srcp, dest, destp, sk->sk_state, tp->write_seq - tp->snd_una, rx_queue, timer_active, - jiffies_to_clock_t(timer_expires - jiffies), + jiffies_delta_to_clock_t(timer_expires - jiffies), icsk->icsk_retransmits, - sock_i_uid(sk), + from_kuid_munged(seq_user_ns(f), sock_i_uid(sk)), icsk->icsk_probes_out, sock_i_ino(sk), atomic_read(&sk->sk_refcnt), sk, @@ -2458,7 +2677,9 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) jiffies_to_clock_t(icsk->icsk_ack.ato), (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong, tp->snd_cwnd, - tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh, + sk->sk_state == TCP_LISTEN ? + (fastopenq ? fastopenq->max_qlen : 0) : + (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh), len); } @@ -2467,10 +2688,7 @@ static void get_timewait4_sock(const struct inet_timewait_sock *tw, { __be32 dest, src; __u16 destp, srcp; - int ttd = tw->tw_ttd - jiffies; - - if (ttd < 0) - ttd = 0; + long delta = tw->tw_ttd - jiffies; dest = tw->tw_daddr; src = tw->tw_rcv_saddr; @@ -2480,7 +2698,7 @@ static void get_timewait4_sock(const struct inet_timewait_sock *tw, seq_printf(f, "%4d: %08X:%04X %08X:%04X" " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n", i, src, srcp, dest, destp, tw->tw_substate, 0, 0, - 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, + 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, atomic_read(&tw->tw_refcnt), tw, len); } @@ -2560,39 +2778,6 @@ void tcp4_proc_exit(void) } #endif /* CONFIG_PROC_FS */ -struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) -{ - const struct iphdr *iph = skb_gro_network_header(skb); - - switch (skb->ip_summed) { - case CHECKSUM_COMPLETE: - if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr, - skb->csum)) { - skb->ip_summed = CHECKSUM_UNNECESSARY; - break; - } - - /* fall through */ - case CHECKSUM_NONE: - NAPI_GRO_CB(skb)->flush = 1; - return NULL; - } - - return tcp_gro_receive(head, skb); -} - -int tcp4_gro_complete(struct sk_buff *skb) -{ - const struct iphdr *iph = ip_hdr(skb); - struct tcphdr *th = tcp_hdr(skb); - - th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb), - iph->saddr, iph->daddr, 0); - skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; - - return tcp_gro_complete(skb); -} - struct proto tcp_prot = { .name = "TCP", .owner = THIS_MODULE, @@ -2616,6 +2801,7 @@ struct proto tcp_prot = { .unhash = inet_unhash, .get_port = inet_csk_get_port, .enter_memory_pressure = tcp_enter_memory_pressure, + .stream_memory_free = tcp_stream_memory_free, .sockets_allocated = &tcp_sockets_allocated, .orphan_count = &tcp_orphan_count, .memory_allocated = &tcp_memory_allocated, @@ -2633,7 +2819,7 @@ struct proto tcp_prot = { .compat_setsockopt = compat_tcp_setsockopt, .compat_getsockopt = compat_tcp_getsockopt, #endif -#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM +#ifdef CONFIG_MEMCG_KMEM .init_cgroup = tcp_init_cgroup, .destroy_cgroup = tcp_destroy_cgroup, .proto_cgroup = tcp_proto_cgroup, @@ -2643,6 +2829,7 @@ EXPORT_SYMBOL(tcp_prot); static int __net_init tcp_sk_init(struct net *net) { + net->ipv4.sysctl_tcp_ecn = 2; return 0; } |