| /* |
| * Copyright (C)2004 USAGI/WIDE Project |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Author: |
| * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/ipv6.h> |
| #include <linux/in6.h> |
| #include <linux/netfilter.h> |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/icmp.h> |
| #include <net/ipv6.h> |
| #include <net/inet_frag.h> |
| |
| #include <linux/netfilter_bridge.h> |
| #include <linux/netfilter_ipv6.h> |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| #include <net/netfilter/nf_conntrack.h> |
| #include <net/netfilter/nf_conntrack_helper.h> |
| #include <net/netfilter/nf_conntrack_l4proto.h> |
| #include <net/netfilter/nf_conntrack_l3proto.h> |
| #include <net/netfilter/nf_conntrack_core.h> |
| #include <net/netfilter/nf_conntrack_zones.h> |
| #include <net/netfilter/nf_conntrack_seqadj.h> |
| #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> |
| #include <net/netfilter/nf_nat_helper.h> |
| #include <net/netfilter/ipv6/nf_defrag_ipv6.h> |
| #include <net/netfilter/nf_log.h> |
| |
| static int conntrack6_net_id; |
| static DEFINE_MUTEX(register_ipv6_hooks); |
| |
| struct conntrack6_net { |
| unsigned int users; |
| }; |
| |
| static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff, |
| struct nf_conntrack_tuple *tuple) |
| { |
| const u_int32_t *ap; |
| u_int32_t _addrs[8]; |
| |
| ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr), |
| sizeof(_addrs), _addrs); |
| if (ap == NULL) |
| return false; |
| |
| memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6)); |
| memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6)); |
| |
| return true; |
| } |
| |
| static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple, |
| const struct nf_conntrack_tuple *orig) |
| { |
| memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6)); |
| memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6)); |
| |
| return true; |
| } |
| |
| static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff, |
| unsigned int *dataoff, u_int8_t *protonum) |
| { |
| unsigned int extoff = nhoff + sizeof(struct ipv6hdr); |
| __be16 frag_off; |
| int protoff; |
| u8 nexthdr; |
| |
| if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr), |
| &nexthdr, sizeof(nexthdr)) != 0) { |
| pr_debug("ip6_conntrack_core: can't get nexthdr\n"); |
| return -NF_ACCEPT; |
| } |
| protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off); |
| /* |
| * (protoff == skb->len) means the packet has not data, just |
| * IPv6 and possibly extensions headers, but it is tracked anyway |
| */ |
| if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { |
| pr_debug("ip6_conntrack_core: can't find proto in pkt\n"); |
| return -NF_ACCEPT; |
| } |
| |
| *dataoff = protoff; |
| *protonum = nexthdr; |
| return NF_ACCEPT; |
| } |
| |
| static unsigned int ipv6_helper(void *priv, |
| struct sk_buff *skb, |
| const struct nf_hook_state *state) |
| { |
| struct nf_conn *ct; |
| const struct nf_conn_help *help; |
| const struct nf_conntrack_helper *helper; |
| enum ip_conntrack_info ctinfo; |
| __be16 frag_off; |
| int protoff; |
| u8 nexthdr; |
| |
| /* This is where we call the helper: as the packet goes out. */ |
| ct = nf_ct_get(skb, &ctinfo); |
| if (!ct || ctinfo == IP_CT_RELATED_REPLY) |
| return NF_ACCEPT; |
| |
| help = nfct_help(ct); |
| if (!help) |
| return NF_ACCEPT; |
| /* rcu_read_lock()ed by nf_hook_thresh */ |
| helper = rcu_dereference(help->helper); |
| if (!helper) |
| return NF_ACCEPT; |
| |
| nexthdr = ipv6_hdr(skb)->nexthdr; |
| protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, |
| &frag_off); |
| if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { |
| pr_debug("proto header not found\n"); |
| return NF_ACCEPT; |
| } |
| |
| return helper->help(skb, protoff, ct, ctinfo); |
| } |
| |
| static unsigned int ipv6_confirm(void *priv, |
| struct sk_buff *skb, |
| const struct nf_hook_state *state) |
| { |
| struct nf_conn *ct; |
| enum ip_conntrack_info ctinfo; |
| unsigned char pnum = ipv6_hdr(skb)->nexthdr; |
| int protoff; |
| __be16 frag_off; |
| |
| ct = nf_ct_get(skb, &ctinfo); |
| if (!ct || ctinfo == IP_CT_RELATED_REPLY) |
| goto out; |
| |
| protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, |
| &frag_off); |
| if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { |
| pr_debug("proto header not found\n"); |
| goto out; |
| } |
| |
| /* adjust seqs for loopback traffic only in outgoing direction */ |
| if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) && |
| !nf_is_loopback_packet(skb)) { |
| if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) { |
| NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop); |
| return NF_DROP; |
| } |
| } |
| out: |
| /* We've seen it coming out the other side: confirm it */ |
| return nf_conntrack_confirm(skb); |
| } |
| |
| static unsigned int ipv6_conntrack_in(void *priv, |
| struct sk_buff *skb, |
| const struct nf_hook_state *state) |
| { |
| return nf_conntrack_in(state->net, PF_INET6, state->hook, skb); |
| } |
| |
| static unsigned int ipv6_conntrack_local(void *priv, |
| struct sk_buff *skb, |
| const struct nf_hook_state *state) |
| { |
| return nf_conntrack_in(state->net, PF_INET6, state->hook, skb); |
| } |
| |
| static const struct nf_hook_ops ipv6_conntrack_ops[] = { |
| { |
| .hook = ipv6_conntrack_in, |
| .pf = NFPROTO_IPV6, |
| .hooknum = NF_INET_PRE_ROUTING, |
| .priority = NF_IP6_PRI_CONNTRACK, |
| }, |
| { |
| .hook = ipv6_conntrack_local, |
| .pf = NFPROTO_IPV6, |
| .hooknum = NF_INET_LOCAL_OUT, |
| .priority = NF_IP6_PRI_CONNTRACK, |
| }, |
| { |
| .hook = ipv6_helper, |
| .pf = NFPROTO_IPV6, |
| .hooknum = NF_INET_POST_ROUTING, |
| .priority = NF_IP6_PRI_CONNTRACK_HELPER, |
| }, |
| { |
| .hook = ipv6_confirm, |
| .pf = NFPROTO_IPV6, |
| .hooknum = NF_INET_POST_ROUTING, |
| .priority = NF_IP6_PRI_LAST, |
| }, |
| { |
| .hook = ipv6_helper, |
| .pf = NFPROTO_IPV6, |
| .hooknum = NF_INET_LOCAL_IN, |
| .priority = NF_IP6_PRI_CONNTRACK_HELPER, |
| }, |
| { |
| .hook = ipv6_confirm, |
| .pf = NFPROTO_IPV6, |
| .hooknum = NF_INET_LOCAL_IN, |
| .priority = NF_IP6_PRI_LAST-1, |
| }, |
| }; |
| |
| static int |
| ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len) |
| { |
| struct nf_conntrack_tuple tuple = { .src.l3num = NFPROTO_IPV6 }; |
| const struct ipv6_pinfo *inet6 = inet6_sk(sk); |
| const struct inet_sock *inet = inet_sk(sk); |
| const struct nf_conntrack_tuple_hash *h; |
| struct sockaddr_in6 sin6; |
| struct nf_conn *ct; |
| __be32 flow_label; |
| int bound_dev_if; |
| |
| lock_sock(sk); |
| tuple.src.u3.in6 = sk->sk_v6_rcv_saddr; |
| tuple.src.u.tcp.port = inet->inet_sport; |
| tuple.dst.u3.in6 = sk->sk_v6_daddr; |
| tuple.dst.u.tcp.port = inet->inet_dport; |
| tuple.dst.protonum = sk->sk_protocol; |
| bound_dev_if = sk->sk_bound_dev_if; |
| flow_label = inet6->flow_label; |
| release_sock(sk); |
| |
| if (tuple.dst.protonum != IPPROTO_TCP && |
| tuple.dst.protonum != IPPROTO_SCTP) |
| return -ENOPROTOOPT; |
| |
| if (*len < 0 || (unsigned int) *len < sizeof(sin6)) |
| return -EINVAL; |
| |
| h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple); |
| if (!h) { |
| pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n", |
| &tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port), |
| &tuple.dst.u3.ip6, ntohs(tuple.dst.u.tcp.port)); |
| return -ENOENT; |
| } |
| |
| ct = nf_ct_tuplehash_to_ctrack(h); |
| |
| sin6.sin6_family = AF_INET6; |
| sin6.sin6_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port; |
| sin6.sin6_flowinfo = flow_label & IPV6_FLOWINFO_MASK; |
| memcpy(&sin6.sin6_addr, |
| &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6, |
| sizeof(sin6.sin6_addr)); |
| |
| nf_ct_put(ct); |
| sin6.sin6_scope_id = ipv6_iface_scope_id(&sin6.sin6_addr, bound_dev_if); |
| return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0; |
| } |
| |
| #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
| |
| #include <linux/netfilter/nfnetlink.h> |
| #include <linux/netfilter/nfnetlink_conntrack.h> |
| |
| static int ipv6_tuple_to_nlattr(struct sk_buff *skb, |
| const struct nf_conntrack_tuple *tuple) |
| { |
| if (nla_put_in6_addr(skb, CTA_IP_V6_SRC, &tuple->src.u3.in6) || |
| nla_put_in6_addr(skb, CTA_IP_V6_DST, &tuple->dst.u3.in6)) |
| goto nla_put_failure; |
| return 0; |
| |
| nla_put_failure: |
| return -1; |
| } |
| |
| static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = { |
| [CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 }, |
| [CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 }, |
| }; |
| |
| static int ipv6_nlattr_to_tuple(struct nlattr *tb[], |
| struct nf_conntrack_tuple *t) |
| { |
| if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST]) |
| return -EINVAL; |
| |
| t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]); |
| t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]); |
| |
| return 0; |
| } |
| #endif |
| |
| static int ipv6_hooks_register(struct net *net) |
| { |
| struct conntrack6_net *cnet = net_generic(net, conntrack6_net_id); |
| int err = 0; |
| |
| mutex_lock(®ister_ipv6_hooks); |
| cnet->users++; |
| if (cnet->users > 1) |
| goto out_unlock; |
| |
| err = nf_defrag_ipv6_enable(net); |
| if (err < 0) { |
| cnet->users = 0; |
| goto out_unlock; |
| } |
| |
| err = nf_register_net_hooks(net, ipv6_conntrack_ops, |
| ARRAY_SIZE(ipv6_conntrack_ops)); |
| if (err) |
| cnet->users = 0; |
| out_unlock: |
| mutex_unlock(®ister_ipv6_hooks); |
| return err; |
| } |
| |
| static void ipv6_hooks_unregister(struct net *net) |
| { |
| struct conntrack6_net *cnet = net_generic(net, conntrack6_net_id); |
| |
| mutex_lock(®ister_ipv6_hooks); |
| if (cnet->users && (--cnet->users == 0)) |
| nf_unregister_net_hooks(net, ipv6_conntrack_ops, |
| ARRAY_SIZE(ipv6_conntrack_ops)); |
| mutex_unlock(®ister_ipv6_hooks); |
| } |
| |
| const struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 = { |
| .l3proto = PF_INET6, |
| .pkt_to_tuple = ipv6_pkt_to_tuple, |
| .invert_tuple = ipv6_invert_tuple, |
| .get_l4proto = ipv6_get_l4proto, |
| #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
| .tuple_to_nlattr = ipv6_tuple_to_nlattr, |
| .nlattr_to_tuple = ipv6_nlattr_to_tuple, |
| .nla_policy = ipv6_nla_policy, |
| .nla_size = NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])) + |
| NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])), |
| #endif |
| .net_ns_get = ipv6_hooks_register, |
| .net_ns_put = ipv6_hooks_unregister, |
| .me = THIS_MODULE, |
| }; |
| |
| MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6)); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>"); |
| |
| static struct nf_sockopt_ops so_getorigdst6 = { |
| .pf = NFPROTO_IPV6, |
| .get_optmin = IP6T_SO_ORIGINAL_DST, |
| .get_optmax = IP6T_SO_ORIGINAL_DST + 1, |
| .get = ipv6_getorigdst, |
| .owner = THIS_MODULE, |
| }; |
| |
| static const struct nf_conntrack_l4proto * const builtin_l4proto6[] = { |
| &nf_conntrack_l4proto_tcp6, |
| &nf_conntrack_l4proto_udp6, |
| &nf_conntrack_l4proto_icmpv6, |
| #ifdef CONFIG_NF_CT_PROTO_DCCP |
| &nf_conntrack_l4proto_dccp6, |
| #endif |
| #ifdef CONFIG_NF_CT_PROTO_SCTP |
| &nf_conntrack_l4proto_sctp6, |
| #endif |
| #ifdef CONFIG_NF_CT_PROTO_UDPLITE |
| &nf_conntrack_l4proto_udplite6, |
| #endif |
| }; |
| |
| static int ipv6_net_init(struct net *net) |
| { |
| return nf_ct_l4proto_pernet_register(net, builtin_l4proto6, |
| ARRAY_SIZE(builtin_l4proto6)); |
| } |
| |
| static void ipv6_net_exit(struct net *net) |
| { |
| nf_ct_l4proto_pernet_unregister(net, builtin_l4proto6, |
| ARRAY_SIZE(builtin_l4proto6)); |
| } |
| |
| static struct pernet_operations ipv6_net_ops = { |
| .init = ipv6_net_init, |
| .exit = ipv6_net_exit, |
| .id = &conntrack6_net_id, |
| .size = sizeof(struct conntrack6_net), |
| }; |
| |
| static int __init nf_conntrack_l3proto_ipv6_init(void) |
| { |
| int ret = 0; |
| |
| need_conntrack(); |
| |
| #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
| if (WARN_ON(nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1) != |
| nf_conntrack_l3proto_ipv6.nla_size)) |
| return -EINVAL; |
| #endif |
| |
| ret = nf_register_sockopt(&so_getorigdst6); |
| if (ret < 0) { |
| pr_err("Unable to register netfilter socket option\n"); |
| return ret; |
| } |
| |
| ret = register_pernet_subsys(&ipv6_net_ops); |
| if (ret < 0) |
| goto cleanup_sockopt; |
| |
| ret = nf_ct_l4proto_register(builtin_l4proto6, |
| ARRAY_SIZE(builtin_l4proto6)); |
| if (ret < 0) |
| goto cleanup_pernet; |
| |
| ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv6); |
| if (ret < 0) { |
| pr_err("nf_conntrack_ipv6: can't register ipv6 proto.\n"); |
| goto cleanup_l4proto; |
| } |
| return ret; |
| cleanup_l4proto: |
| nf_ct_l4proto_unregister(builtin_l4proto6, |
| ARRAY_SIZE(builtin_l4proto6)); |
| cleanup_pernet: |
| unregister_pernet_subsys(&ipv6_net_ops); |
| cleanup_sockopt: |
| nf_unregister_sockopt(&so_getorigdst6); |
| return ret; |
| } |
| |
| static void __exit nf_conntrack_l3proto_ipv6_fini(void) |
| { |
| synchronize_net(); |
| nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv6); |
| nf_ct_l4proto_unregister(builtin_l4proto6, |
| ARRAY_SIZE(builtin_l4proto6)); |
| unregister_pernet_subsys(&ipv6_net_ops); |
| nf_unregister_sockopt(&so_getorigdst6); |
| } |
| |
| module_init(nf_conntrack_l3proto_ipv6_init); |
| module_exit(nf_conntrack_l3proto_ipv6_fini); |