ipv4: Implement IP_TRANSPARENT socket option

This patch introduces the IP_TRANSPARENT socket option: enabling that
will make the IPv4 routing omit the non-local source address check on
output. Setting IP_TRANSPARENT requires NET_ADMIN capability.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 5 insertions, 2 deletions

diff --git a/include/linux/in.h b/include/linux/in.h
index 4065313cd7e..db458beef19 100644
--- a/include/linux/in.h
+++ b/include/linux/in.h
@@ -75,6 +75,7 @@ struct in_addr {
 #define IP_IPSEC_POLICY 16
 #define IP_XFRM_POLICY  17
 #define IP_PASSSEC      18
+#define IP_TRANSPARENT  19
 
 /* BSD compatibility */
 #define IP_RECVRETOPTS  IP_RETOPTS
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 643e26be058..e97b66e2a9d 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -129,7 +129,8 @@ struct inet_sock {
                                 is_icsk:1,
                                 freebind:1,
                                 hdrincl:1,
-                                mc_loop:1;
+                                mc_loop:1,
+                                transparent:1;
         int                     mc_index;
         __be32                  mc_addr;
         struct ip_mc_socklist   *mc_list;
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 91324908fcc..80e4977631b 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -128,7 +128,8 @@ struct inet_timewait_sock {
         __be16                  tw_dport;
         __u16                   tw_num;
         /* And these are ours. */
-        __u8                    tw_ipv6only:1;
+        __u8                    tw_ipv6only:1,
+                                tw_transparent:1;
         /* 15 bits hole, try to pack */
         __u16                   tw_ipv6_offset;
         unsigned long           tw_ttd;