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authorDavid S. Miller <davem@davemloft.net>2012-06-29 01:32:45 -0700
committerDavid S. Miller <davem@davemloft.net>2012-06-29 01:36:36 -0700
commit7a9bc9b81a5bc6e44ebc80ef781332e4385083f2 (patch)
tree1342c672823d47bfb112fee63951af9f6a3eb590 /net/ipv4/fib_semantics.c
parentb8c8430726e5bd552e01dacc5a44f3f83f7446ca (diff)
ipv4: Elide fib_validate_source() completely when possible.
If rpfilter is off (or the SKB has an IPSEC path) and there are not tclassid users, we don't have to do anything at all when fib_validate_source() is invoked besides setting the itag to zero. We monitor tclassid uses with a counter (modified only under RTNL and marked __read_mostly) and we protect the fib_validate_source() real work with a test against this counter and whether rpfilter is to be done. Having a way to know whether we need no tclassid processing or not also opens the door for future optimized rpfilter algorithms that do not perform full FIB lookups. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/fib_semantics.c')
-rw-r--r--net/ipv4/fib_semantics.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 415f8230fc88..c46c20b6b0b6 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -163,6 +163,12 @@ void free_fib_info(struct fib_info *fi)
return;
}
fib_info_cnt--;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ change_nexthops(fi) {
+ if (nexthop_nh->nh_tclassid)
+ fib_num_tclassid_users--;
+ } endfor_nexthops(fi);
+#endif
call_rcu(&fi->rcu, free_fib_info_rcu);
}
@@ -421,6 +427,8 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
#ifdef CONFIG_IP_ROUTE_CLASSID
nla = nla_find(attrs, attrlen, RTA_FLOW);
nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0;
+ if (nexthop_nh->nh_tclassid)
+ fib_num_tclassid_users++;
#endif
}
@@ -815,6 +823,8 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
nh->nh_flags = cfg->fc_flags;
#ifdef CONFIG_IP_ROUTE_CLASSID
nh->nh_tclassid = cfg->fc_flow;
+ if (nh->nh_tclassid)
+ fib_num_tclassid_users++;
#endif
#ifdef CONFIG_IP_ROUTE_MULTIPATH
nh->nh_weight = 1;