| #include <net/netfilter/nf_tproxy.h> |
| #include <linux/module.h> |
| #include <net/inet6_hashtables.h> |
| #include <net/addrconf.h> |
| #include <net/udp.h> |
| #include <net/tcp.h> |
| |
| const struct in6_addr * |
| nf_tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr, |
| const struct in6_addr *daddr) |
| { |
| struct inet6_dev *indev; |
| struct inet6_ifaddr *ifa; |
| struct in6_addr *laddr; |
| |
| if (!ipv6_addr_any(user_laddr)) |
| return user_laddr; |
| laddr = NULL; |
| |
| indev = __in6_dev_get(skb->dev); |
| if (indev) { |
| read_lock_bh(&indev->lock); |
| list_for_each_entry(ifa, &indev->addr_list, if_list) { |
| if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED)) |
| continue; |
| |
| laddr = &ifa->addr; |
| break; |
| } |
| read_unlock_bh(&indev->lock); |
| } |
| |
| return laddr ? laddr : daddr; |
| } |
| EXPORT_SYMBOL_GPL(nf_tproxy_laddr6); |
| |
| struct sock * |
| nf_tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff, |
| struct net *net, |
| const struct in6_addr *laddr, |
| const __be16 lport, |
| struct sock *sk) |
| { |
| const struct ipv6hdr *iph = ipv6_hdr(skb); |
| struct tcphdr _hdr, *hp; |
| |
| hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr); |
| if (hp == NULL) { |
| inet_twsk_put(inet_twsk(sk)); |
| return NULL; |
| } |
| |
| if (hp->syn && !hp->rst && !hp->ack && !hp->fin) { |
| /* SYN to a TIME_WAIT socket, we'd rather redirect it |
| * to a listener socket if there's one */ |
| struct sock *sk2; |
| |
| sk2 = nf_tproxy_get_sock_v6(net, skb, thoff, tproto, |
| &iph->saddr, |
| nf_tproxy_laddr6(skb, laddr, &iph->daddr), |
| hp->source, |
| lport ? lport : hp->dest, |
| skb->dev, NF_TPROXY_LOOKUP_LISTENER); |
| if (sk2) { |
| inet_twsk_deschedule_put(inet_twsk(sk)); |
| sk = sk2; |
| } |
| } |
| |
| return sk; |
| } |
| EXPORT_SYMBOL_GPL(nf_tproxy_handle_time_wait6); |
| |
| struct sock * |
| nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, |
| const u8 protocol, |
| const struct in6_addr *saddr, const struct in6_addr *daddr, |
| const __be16 sport, const __be16 dport, |
| const struct net_device *in, |
| const enum nf_tproxy_lookup_t lookup_type) |
| { |
| struct sock *sk; |
| |
| switch (protocol) { |
| case IPPROTO_TCP: { |
| struct tcphdr _hdr, *hp; |
| |
| hp = skb_header_pointer(skb, thoff, |
| sizeof(struct tcphdr), &_hdr); |
| if (hp == NULL) |
| return NULL; |
| |
| switch (lookup_type) { |
| case NF_TPROXY_LOOKUP_LISTENER: |
| sk = inet6_lookup_listener(net, &tcp_hashinfo, skb, |
| thoff + __tcp_hdrlen(hp), |
| saddr, sport, |
| daddr, ntohs(dport), |
| in->ifindex, 0); |
| |
| if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) |
| sk = NULL; |
| /* NOTE: we return listeners even if bound to |
| * 0.0.0.0, those are filtered out in |
| * xt_socket, since xt_TPROXY needs 0 bound |
| * listeners too |
| */ |
| break; |
| case NF_TPROXY_LOOKUP_ESTABLISHED: |
| sk = __inet6_lookup_established(net, &tcp_hashinfo, |
| saddr, sport, daddr, ntohs(dport), |
| in->ifindex, 0); |
| break; |
| default: |
| BUG(); |
| } |
| break; |
| } |
| case IPPROTO_UDP: |
| sk = udp6_lib_lookup(net, saddr, sport, daddr, dport, |
| in->ifindex); |
| if (sk) { |
| int connected = (sk->sk_state == TCP_ESTABLISHED); |
| int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr); |
| |
| /* NOTE: we return listeners even if bound to |
| * 0.0.0.0, those are filtered out in |
| * xt_socket, since xt_TPROXY needs 0 bound |
| * listeners too |
| */ |
| if ((lookup_type == NF_TPROXY_LOOKUP_ESTABLISHED && (!connected || wildcard)) || |
| (lookup_type == NF_TPROXY_LOOKUP_LISTENER && connected)) { |
| sock_put(sk); |
| sk = NULL; |
| } |
| } |
| break; |
| default: |
| WARN_ON(1); |
| sk = NULL; |
| } |
| |
| pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n", |
| protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk); |
| |
| return sk; |
| } |
| EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v6); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs"); |
| MODULE_DESCRIPTION("Netfilter IPv4 transparent proxy support"); |