// SPDX-License-Identifier: GPL-2.0-only #include #include #include #include #include #include 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");