diff options
Diffstat (limited to 'net/ipv6/netfilter/nf_tproxy_ipv6.c')
| -rw-r--r-- | net/ipv6/netfilter/nf_tproxy_ipv6.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/nf_tproxy_ipv6.c b/net/ipv6/netfilter/nf_tproxy_ipv6.c new file mode 100644 index 0000000000000..bf1d6c421e3bd --- /dev/null +++ b/net/ipv6/netfilter/nf_tproxy_ipv6.c @@ -0,0 +1,146 @@ +#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, hp, 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, void *hp, + 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; + struct tcphdr *tcph; + + switch (protocol) { + case IPPROTO_TCP: + switch (lookup_type) { + case NF_TPROXY_LOOKUP_LISTENER: + tcph = hp; + sk = inet6_lookup_listener(net, &tcp_hashinfo, skb, + thoff + __tcp_hdrlen(tcph), + 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"); |