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| author |   David S. Miller <davem@davemloft.net> | 2012-06-29 01:32:45 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-06-29 01:36:36 -0700 |
| commit | 7a9bc9b81a5bc6e44ebc80ef781332e4385083f2 (patch) | |
| tree | 1342c672823d47bfb112fee63951af9f6a3eb590 /net/ipv4/fib_semantics.c | |
| parent | net: l2tp_eth: provide tx_dropped counter (diff) | |
| download | linux-dev-7a9bc9b81a5bc6e44ebc80ef781332e4385083f2.tar.xz linux-dev-7a9bc9b81a5bc6e44ebc80ef781332e4385083f2.zip | |
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 '')
| -rw-r--r-- | net/ipv4/fib_semantics.c | 10 |
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; |