net: fib_rules: decouple address families from real address families

Decouple the address family values used for fib_rules from the real
address families in socket.h. This allows to use fib_rules for
code that is not a real address family without increasing AF_MAX/NPROTO.

Values up to 127 are reserved for real address families and map directly
to the corresponding AF value, values starting from 128 are for other
uses. rtnetlink is changed to invoke the AF_UNSPEC dumpit/doit handlers
for these families.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 5 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index bf919b6acea2..78c85985cb30 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -118,7 +118,11 @@ static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
 {
         struct rtnl_link *tab;
 
-        tab = rtnl_msg_handlers[protocol];
+        if (protocol < NPROTO)
+                tab = rtnl_msg_handlers[protocol];
+        else
+                tab = NULL;
+
         if (tab == NULL || tab[msgindex].doit == NULL)
                 tab = rtnl_msg_handlers[PF_UNSPEC];
 
@@ -129,7 +133,11 @@ static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
 {
         struct rtnl_link *tab;
 
-        tab = rtnl_msg_handlers[protocol];
+        if (protocol < NPROTO)
+                tab = rtnl_msg_handlers[protocol];
+        else
+                tab = NULL;
+
         if (tab == NULL || tab[msgindex].dumpit == NULL)
                 tab = rtnl_msg_handlers[PF_UNSPEC];
 
@@ -1444,9 +1452,6 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 return 0;
 
         family = ((struct rtgenmsg *)NLMSG_DATA(nlh))->rtgen_family;
-        if (family >= NPROTO)
-                return -EAFNOSUPPORT;
-
         sz_idx = type>>2;
         kind = type&3;