tproxy: added tproxy sockopt interface in the IPV6 layer

Support for IPV6_RECVORIGDSTADDR sockopt for UDP sockets were contributed by
Harry Mason.

Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

2 files changed, 42 insertions, 0 deletions

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index ef371aa01ac5..320bdb877eed 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -577,6 +577,25 @@ int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
                 u8 *ptr = nh + opt->dst1;
                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
         }
+        if (np->rxopt.bits.rxorigdstaddr) {
+                struct sockaddr_in6 sin6;
+                u16 *ports = (u16 *) skb_transport_header(skb);
+
+                if (skb_transport_offset(skb) + 4 <= skb->len) {
+                        /* All current transport protocols have the port numbers in the
+                         * first four bytes of the transport header and this function is
+                         * written with this assumption in mind.
+                         */
+
+                        sin6.sin6_family = AF_INET6;
+                        ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
+                        sin6.sin6_port = ports[1];
+                        sin6.sin6_flowinfo = 0;
+                        sin6.sin6_scope_id = 0;
+
+                        put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
+                }
+        }
         return 0;
 }
 
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index a7f66bc8f0b0..0553867a317f 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -342,6 +342,21 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
                 retv = 0;
                 break;
 
+        case IPV6_TRANSPARENT:
+                if (optlen < sizeof(int))
+                        goto e_inval;
+                /* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
+                inet_sk(sk)->transparent = valbool;
+                retv = 0;
+                break;
+
+        case IPV6_RECVORIGDSTADDR:
+                if (optlen < sizeof(int))
+                        goto e_inval;
+                np->rxopt.bits.rxorigdstaddr = valbool;
+                retv = 0;
+                break;
+
         case IPV6_HOPOPTS:
         case IPV6_RTHDRDSTOPTS:
         case IPV6_RTHDR:
@@ -1104,6 +1119,14 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
                 break;
         }
 
+        case IPV6_TRANSPARENT:
+                val = inet_sk(sk)->transparent;
+                break;
+
+        case IPV6_RECVORIGDSTADDR:
+                val = np->rxopt.bits.rxorigdstaddr;
+                break;
+
         case IPV6_UNICAST_HOPS:
         case IPV6_MULTICAST_HOPS:
         {