[PATCH] Consolidate the ip6_pol_route_(input|output) pair

[PATCH] Consolidate the ip6_pol_route_(input|output) pair

[Pavel Emelyanov]

The difference in both functions is in the "id" passed to
the rt6_select, so just pass it as an extra argument from
two outer helpers.

This is minus 60 lines of code and 360 bytes of .text

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---

 net/ipv6/route.c |   77 ++++++-------------------------------------------------
 1 files changed, 9 insertions(+), 68 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 6ff19f9..cce9941 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -663,7 +663,7 @@ static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, struct in6_addr *d
 	return rt;
 }
 
-static struct rt6_info *ip6_pol_route_input(struct fib6_table *table,
+static struct rt6_info *ip6_pol_route(struct fib6_table *table, int oif,
 					    struct flowi *fl, int flags)
 {
 	struct fib6_node *fn;
@@ -682,7 +682,7 @@ restart_2:
 	fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
 
 restart:
-	rt = rt6_select(fn, fl->iif, strict | reachable);
+	rt = rt6_select(fn, oif, strict | reachable);
 	BACKTRACK(&fl->fl6_src);
 	if (rt == &ip6_null_entry ||
 	    rt->rt6i_flags & RTF_CACHE)
@@ -735,6 +735,12 @@ out2:
 	return rt;
 }
 
+static struct rt6_info *ip6_pol_route_input(struct fib6_table *table,
+					    struct flowi *fl, int flags)
+{
+	return ip6_pol_route(table, fl->iif, fl, flags);
+}
+
 void ip6_route_input(struct sk_buff *skb)
 {
 	struct ipv6hdr *iph = ipv6_hdr(skb);
@@ -761,72 +767,7 @@ void ip6_route_input(struct sk_buff *skb)
 static struct rt6_info *ip6_pol_route_output(struct fib6_table *table,
 					     struct flowi *fl, int flags)
 {
-	struct fib6_node *fn;
-	struct rt6_info *rt, *nrt;
-	int strict = 0;
-	int attempts = 3;
-	int err;
-	int reachable = ipv6_devconf.forwarding ? 0 : RT6_LOOKUP_F_REACHABLE;
-
-	strict |= flags & RT6_LOOKUP_F_IFACE;
-
-relookup:
-	read_lock_bh(&table->tb6_lock);
-
-restart_2:
-	fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src);
-
-restart:
-	rt = rt6_select(fn, fl->oif, strict | reachable);
-	BACKTRACK(&fl->fl6_src);
-	if (rt == &ip6_null_entry ||
-	    rt->rt6i_flags & RTF_CACHE)
-		goto out;
-
-	dst_hold(&rt->u.dst);
-	read_unlock_bh(&table->tb6_lock);
-
-	if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
-		nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src);
-	else {
-#if CLONE_OFFLINK_ROUTE
-		nrt = rt6_alloc_clone(rt, &fl->fl6_dst);
-#else
-		goto out2;
-#endif
-	}
-
-	dst_release(&rt->u.dst);
-	rt = nrt ? : &ip6_null_entry;
-
-	dst_hold(&rt->u.dst);
-	if (nrt) {
-		err = ip6_ins_rt(nrt);
-		if (!err)
-			goto out2;
-	}
-
-	if (--attempts <= 0)
-		goto out2;
-
-	/*
-	 * Race condition! In the gap, when table->tb6_lock was
-	 * released someone could insert this route.  Relookup.
-	 */
-	dst_release(&rt->u.dst);
-	goto relookup;
-
-out:
-	if (reachable) {
-		reachable = 0;
-		goto restart_2;
-	}
-	dst_hold(&rt->u.dst);
-	read_unlock_bh(&table->tb6_lock);
-out2:
-	rt->u.dst.lastuse = jiffies;
-	rt->u.dst.__use++;
-	return rt;
+	return ip6_pol_route(table, fl->oif, fl, flags);
 }
 
 struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl)

Re: [PATCH] Consolidate the ip6_pol_route_(input|output) pair

[David Miller]

From: Pavel Emelyanov <xemul@openvz.org>
Date: Mon, 15 Oct 2007 15:55:21 +0400

> The difference in both functions is in the "id" passed to
> the rt6_select, so just pass it as an extra argument from
> two outer helpers.
> 
> This is minus 60 lines of code and 360 bytes of .text
> 
> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

Excellent cleanup, applied!