diff options
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
-rw-r--r-- | net/ipv6/tcp_ipv6.c | 211 |
1 files changed, 103 insertions, 108 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 075ee8a2df3b..2a3f9296df1e 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -146,17 +146,18 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; - struct inet_sock *inet = inet_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); + struct in6_addr *saddr = NULL, *final_p, final; + struct inet_timewait_death_row *tcp_death_row; struct ipv6_pinfo *np = tcp_inet6_sk(sk); + struct inet_sock *inet = inet_sk(sk); struct tcp_sock *tp = tcp_sk(sk); - struct in6_addr *saddr = NULL, *final_p, final; + struct net *net = sock_net(sk); struct ipv6_txoptions *opt; - struct flowi6 fl6; struct dst_entry *dst; + struct flowi6 fl6; int addr_type; int err; - struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; @@ -230,14 +231,15 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, u32 exthdrlen = icsk->icsk_ext_hdr_len; struct sockaddr_in sin; - if (__ipv6_only_sock(sk)) + if (ipv6_only_sock(sk)) return -ENETUNREACH; sin.sin_family = AF_INET; sin.sin_port = usin->sin6_port; sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; - icsk->icsk_af_ops = &ipv6_mapped; + /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ + WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped); if (sk_is_mptcp(sk)) mptcpv6_handle_mapped(sk, true); sk->sk_backlog_rcv = tcp_v4_do_rcv; @@ -249,7 +251,8 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, if (err) { icsk->icsk_ext_hdr_len = exthdrlen; - icsk->icsk_af_ops = &ipv6_specific; + /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ + WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific); if (sk_is_mptcp(sk)) mptcpv6_handle_mapped(sk, false); sk->sk_backlog_rcv = tcp_v6_do_rcv; @@ -280,15 +283,33 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); - dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); + dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p); if (IS_ERR(dst)) { err = PTR_ERR(dst); goto failure; } + tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; + if (!saddr) { + struct inet_bind_hashbucket *prev_addr_hashbucket = NULL; + struct in6_addr prev_v6_rcv_saddr; + + if (icsk->icsk_bind2_hash) { + prev_addr_hashbucket = inet_bhashfn_portaddr(tcp_death_row->hashinfo, + sk, net, inet->inet_num); + prev_v6_rcv_saddr = sk->sk_v6_rcv_saddr; + } saddr = &fl6.saddr; sk->sk_v6_rcv_saddr = *saddr; + + if (prev_addr_hashbucket) { + err = inet_bhash2_update_saddr(prev_addr_hashbucket, sk); + if (err) { + sk->sk_v6_rcv_saddr = prev_v6_rcv_saddr; + goto failure; + } + } } /* set the source address */ @@ -321,8 +342,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, sk->sk_v6_daddr.s6_addr32, inet->inet_sport, inet->inet_dport)); - tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk), - np->saddr.s6_addr32, + tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32, sk->sk_v6_daddr.s6_addr32); } @@ -385,7 +405,7 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, bool fatal; int err; - sk = __inet6_lookup_established(net, &tcp_hashinfo, + sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, &hdr->daddr, th->dest, &hdr->saddr, ntohs(th->source), skb->dev->ifindex, inet6_sdif(skb)); @@ -545,7 +565,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, if (np->repflow && ireq->pktopts) fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); - tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ? + tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ? (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | (np->tclass & INET_ECN_MASK) : np->tclass; @@ -772,57 +792,6 @@ clear_hash_noput: #endif -static bool tcp_v6_inbound_md5_hash(const struct sock *sk, - const struct sk_buff *skb, - int dif, int sdif) -{ -#ifdef CONFIG_TCP_MD5SIG - const __u8 *hash_location = NULL; - struct tcp_md5sig_key *hash_expected; - const struct ipv6hdr *ip6h = ipv6_hdr(skb); - const struct tcphdr *th = tcp_hdr(skb); - int genhash, l3index; - u8 newhash[16]; - - /* sdif set, means packet ingressed via a device - * in an L3 domain and dif is set to the l3mdev - */ - l3index = sdif ? dif : 0; - - hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index); - hash_location = tcp_parse_md5sig_option(th); - - /* We've parsed the options - do we have a hash? */ - if (!hash_expected && !hash_location) - return false; - - if (hash_expected && !hash_location) { - NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); - return true; - } - - if (!hash_expected && hash_location) { - NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); - return true; - } - - /* check the signature */ - genhash = tcp_v6_md5_hash_skb(newhash, - hash_expected, - NULL, skb); - - if (genhash || memcmp(hash_location, newhash, 16) != 0) { - NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE); - net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n", - genhash ? "failed" : "mismatch", - &ip6h->saddr, ntohs(th->source), - &ip6h->daddr, ntohs(th->dest), l3index); - return true; - } -#endif - return false; -} - static void tcp_v6_init_req(struct request_sock *req, const struct sock *sk_listener, struct sk_buff *skb) @@ -891,7 +860,7 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, struct tcp_md5sig_key *key, int rst, - u8 tclass, __be32 label, u32 priority) + u8 tclass, __be32 label, u32 priority, u32 txhash) { const struct tcphdr *th = tcp_hdr(skb); struct tcphdr *t1; @@ -920,12 +889,11 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 } #endif - buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len, - GFP_ATOMIC); + buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); if (!buff) return; - skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len); + skb_reserve(buff, MAX_TCP_HEADER); t1 = skb_push(buff, tot_len); skb_reset_transport_header(buff); @@ -983,15 +951,15 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 } if (sk) { - if (sk->sk_state == TCP_TIME_WAIT) { + if (sk->sk_state == TCP_TIME_WAIT) mark = inet_twsk(sk)->tw_mark; - /* autoflowlabel relies on buff->hash */ - skb_set_hash(buff, inet_twsk(sk)->tw_txhash, - PKT_HASH_TYPE_L4); - } else { + else mark = sk->sk_mark; - } - buff->tstamp = tcp_transmit_time(sk); + skb_set_delivery_time(buff, tcp_transmit_time(sk), true); + } + if (txhash) { + /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */ + skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4); } fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; fl6.fl6_dport = t1->dest; @@ -1003,7 +971,10 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 * Underlying function will use this to retrieve the network * namespace */ - dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL); + if (sk && sk->sk_state != TCP_TIME_WAIT) + dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/ + else + dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL); if (!IS_ERR(dst)) { skb_dst_set(buff, dst); ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, @@ -1032,6 +1003,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) __be32 label = 0; u32 priority = 0; struct net *net; + u32 txhash = 0; int oif = 0; if (th->rst) @@ -1067,11 +1039,10 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) * Incoming packet is checked with md5 hash with finding key, * no RST generated if md5 hash doesn't match. */ - sk1 = inet6_lookup_listener(net, - &tcp_hashinfo, NULL, 0, - &ipv6h->saddr, - th->source, &ipv6h->daddr, - ntohs(th->source), dif, sdif); + sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, + NULL, 0, &ipv6h->saddr, th->source, + &ipv6h->daddr, ntohs(th->source), + dif, sdif); if (!sk1) goto out; @@ -1105,10 +1076,12 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) if (np->repflow) label = ip6_flowlabel(ipv6h); priority = sk->sk_priority; + txhash = sk->sk_hash; } if (sk->sk_state == TCP_TIME_WAIT) { label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); priority = inet_twsk(sk)->tw_priority; + txhash = inet_twsk(sk)->tw_txhash; } } else { if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) @@ -1116,7 +1089,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) } tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, - ipv6_get_dsfield(ipv6h), label, priority); + ipv6_get_dsfield(ipv6h), label, priority, txhash); #ifdef CONFIG_TCP_MD5SIG out: @@ -1127,10 +1100,10 @@ out: static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, struct tcp_md5sig_key *key, u8 tclass, - __be32 label, u32 priority) + __be32 label, u32 priority, u32 txhash) { tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0, - tclass, label, priority); + tclass, label, priority, txhash); } static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) @@ -1142,7 +1115,8 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcp_time_stamp_raw() + tcptw->tw_ts_offset, tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw), - tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority); + tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority, + tw->tw_txhash); inet_twsk_put(tw); } @@ -1169,7 +1143,8 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, tcp_time_stamp_raw() + tcp_rsk(req)->ts_off, req->ts_recent, sk->sk_bound_dev_if, tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index), - ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority); + ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority, + tcp_rsk(req)->txhash); } @@ -1365,7 +1340,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * /* Set ToS of the new socket based upon the value of incoming SYN. * ECT bits are set later in tcp_init_transfer(). */ - if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; /* Clone native IPv6 options from listening socket (if any) @@ -1471,6 +1446,7 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) { struct ipv6_pinfo *np = tcp_inet6_sk(sk); struct sk_buff *opt_skb = NULL; + enum skb_drop_reason reason; struct tcp_sock *tp; /* Imagine: socket is IPv6. IPv4 packet arrives, @@ -1505,6 +1481,7 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) if (np->rxopt.all) opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC)); + reason = SKB_DROP_REASON_NOT_SPECIFIED; if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ struct dst_entry *dst; @@ -1558,9 +1535,10 @@ reset: discard: if (opt_skb) __kfree_skb(opt_skb); - kfree_skb(skb); + kfree_skb_reason(skb, reason); return 0; csum_err: + reason = SKB_DROP_REASON_TCP_CSUM; trace_tcp_bad_csum(skb); TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); @@ -1626,6 +1604,7 @@ static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr, INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) { + enum skb_drop_reason drop_reason; int sdif = inet6_sdif(skb); int dif = inet6_iif(skb); const struct tcphdr *th; @@ -1635,6 +1614,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) int ret; struct net *net = dev_net(skb->dev); + drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; if (skb->pkt_type != PACKET_HOST) goto discard_it; @@ -1648,8 +1628,10 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) th = (const struct tcphdr *)skb->data; - if (unlikely(th->doff < sizeof(struct tcphdr)/4)) + if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { + drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; goto bad_packet; + } if (!pskb_may_pull(skb, th->doff*4)) goto discard_it; @@ -1660,7 +1642,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) hdr = ipv6_hdr(skb); lookup: - sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), + sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th), th->source, th->dest, inet6_iif(skb), sdif, &refcounted); if (!sk) @@ -1676,7 +1658,10 @@ process: struct sock *nsk; sk = req->rsk_listener; - if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) { + drop_reason = tcp_inbound_md5_hash(sk, skb, + &hdr->saddr, &hdr->daddr, + AF_INET6, dif, sdif); + if (drop_reason) { sk_drops_add(sk, skb); reqsk_put(req); goto discard_it; @@ -1705,6 +1690,8 @@ process: hdr = ipv6_hdr(skb); tcp_v6_fill_cb(skb, hdr, th); nsk = tcp_check_req(sk, skb, req, false, &req_stolen); + } else { + drop_reason = SKB_DROP_REASON_SOCKET_FILTER; } if (!nsk) { reqsk_put(req); @@ -1740,14 +1727,20 @@ process: } } - if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) + if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) { + drop_reason = SKB_DROP_REASON_XFRM_POLICY; goto discard_and_relse; + } - if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) + drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr, + AF_INET6, dif, sdif); + if (drop_reason) goto discard_and_relse; - if (tcp_filter(sk, skb)) + if (tcp_filter(sk, skb)) { + drop_reason = SKB_DROP_REASON_SOCKET_FILTER; goto discard_and_relse; + } th = (const struct tcphdr *)skb->data; hdr = ipv6_hdr(skb); tcp_v6_fill_cb(skb, hdr, th); @@ -1761,14 +1754,13 @@ process: sk_incoming_cpu_update(sk); - sk_defer_free_flush(sk); bh_lock_sock_nested(sk); tcp_segs_in(tcp_sk(sk), skb); ret = 0; if (!sock_owned_by_user(sk)) { ret = tcp_v6_do_rcv(sk, skb); } else { - if (tcp_add_backlog(sk, skb)) + if (tcp_add_backlog(sk, skb, &drop_reason)) goto discard_and_relse; } bh_unlock_sock(sk); @@ -1778,6 +1770,7 @@ put_and_return: return ret ? -1 : 0; no_tcp_socket: + drop_reason = SKB_DROP_REASON_NO_SOCKET; if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard_it; @@ -1785,6 +1778,7 @@ no_tcp_socket: if (tcp_checksum_complete(skb)) { csum_error: + drop_reason = SKB_DROP_REASON_TCP_CSUM; trace_tcp_bad_csum(skb); __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); bad_packet: @@ -1794,7 +1788,8 @@ bad_packet: } discard_it: - kfree_skb(skb); + SKB_DR_OR(drop_reason, NOT_SPECIFIED); + kfree_skb_reason(skb, drop_reason); return 0; discard_and_relse: @@ -1805,6 +1800,7 @@ discard_and_relse: do_time_wait: if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { + drop_reason = SKB_DROP_REASON_XFRM_POLICY; inet_twsk_put(inet_twsk(sk)); goto discard_it; } @@ -1821,7 +1817,7 @@ do_time_wait: { struct sock *sk2; - sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, + sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th), &ipv6_hdr(skb)->saddr, th->source, &ipv6_hdr(skb)->daddr, @@ -1852,8 +1848,9 @@ do_time_wait: goto discard_it; } -INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb) +void tcp_v6_early_demux(struct sk_buff *skb) { + struct net *net = dev_net(skb->dev); const struct ipv6hdr *hdr; const struct tcphdr *th; struct sock *sk; @@ -1871,7 +1868,7 @@ INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb) return; /* Note : We use inet6_iif() here, not tcp_v6_iif() */ - sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo, + sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, &hdr->saddr, th->source, &hdr->daddr, ntohs(th->dest), inet6_iif(skb), inet6_sdif(skb)); @@ -2074,7 +2071,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) jiffies_to_clock_t(icsk->icsk_rto), jiffies_to_clock_t(icsk->icsk_ack.ato), (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp), - tp->snd_cwnd, + tcp_snd_cwnd(tp), state == TCP_LISTEN ? fastopenq->max_qlen : (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) @@ -2189,7 +2186,10 @@ struct proto tcpv6_prot = { .leave_memory_pressure = tcp_leave_memory_pressure, .stream_memory_free = tcp_stream_memory_free, .sockets_allocated = &tcp_sockets_allocated, + .memory_allocated = &tcp_memory_allocated, + .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, + .memory_pressure = &tcp_memory_pressure, .orphan_count = &tcp_orphan_count, .sysctl_mem = sysctl_tcp_mem, @@ -2200,18 +2200,13 @@ struct proto tcpv6_prot = { .slab_flags = SLAB_TYPESAFE_BY_RCU, .twsk_prot = &tcp6_timewait_sock_ops, .rsk_prot = &tcp6_request_sock_ops, - .h.hashinfo = &tcp_hashinfo, + .h.hashinfo = NULL, .no_autobind = true, .diag_destroy = tcp_abort, }; EXPORT_SYMBOL_GPL(tcpv6_prot); -/* thinking of making this const? Don't. - * early_demux can change based on sysctl. - */ -static struct inet6_protocol tcpv6_protocol = { - .early_demux = tcp_v6_early_demux, - .early_demux_handler = tcp_v6_early_demux, +static const struct inet6_protocol tcpv6_protocol = { .handler = tcp_v6_rcv, .err_handler = tcp_v6_err, .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, @@ -2239,7 +2234,7 @@ static void __net_exit tcpv6_net_exit(struct net *net) static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) { - inet_twsk_purge(&tcp_hashinfo, AF_INET6); + tcp_twsk_purge(net_exit_list, AF_INET6); } static struct pernet_operations tcpv6_net_ops = { |