From b23dd4fe42b455af5c6e20966b7d6959fa8352ea Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 2 Mar 2011 14:31:35 -0800 Subject: ipv4: Make output route lookup return rtable directly. Instead of on the stack. Signed-off-by: David S. Miller --- net/ipv4/route.c | 100 +++++++++++++++++++++++++++---------------------------- 1 file changed, 49 insertions(+), 51 deletions(-) (limited to 'net/ipv4/route.c') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 63d37004ee6..5090e956f6b 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1014,8 +1014,8 @@ static int slow_chain_length(const struct rtable *head) return length >> FRACT_BITS; } -static int rt_intern_hash(unsigned hash, struct rtable *rt, - struct rtable **rp, struct sk_buff *skb, int ifindex) +static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt, + struct sk_buff *skb, int ifindex) { struct rtable *rth, *cand; struct rtable __rcu **rthp, **candp; @@ -1056,7 +1056,7 @@ restart: printk(KERN_WARNING "Neighbour table failure & not caching routes.\n"); ip_rt_put(rt); - return err; + return ERR_PTR(err); } } @@ -1093,11 +1093,9 @@ restart: spin_unlock_bh(rt_hash_lock_addr(hash)); rt_drop(rt); - if (rp) - *rp = rth; - else + if (skb) skb_dst_set(skb, &rth->dst); - return 0; + return rth; } if (!atomic_read(&rth->dst.__refcnt)) { @@ -1154,7 +1152,7 @@ restart: if (err != -ENOBUFS) { rt_drop(rt); - return err; + return ERR_PTR(err); } /* Neighbour tables are full and nothing @@ -1175,7 +1173,7 @@ restart: if (net_ratelimit()) printk(KERN_WARNING "ipv4: Neighbour table overflow.\n"); rt_drop(rt); - return -ENOBUFS; + return ERR_PTR(-ENOBUFS); } } @@ -1201,11 +1199,9 @@ restart: spin_unlock_bh(rt_hash_lock_addr(hash)); skip_hashing: - if (rp) - *rp = rt; - else + if (skb) skb_dst_set(skb, &rt->dst); - return 0; + return rt; } static atomic_t __rt_peer_genid = ATOMIC_INIT(0); @@ -1896,7 +1892,10 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, RT_CACHE_STAT_INC(in_slow_mc); hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); - return rt_intern_hash(hash, rth, NULL, skb, dev->ifindex); + rth = rt_intern_hash(hash, rth, skb, dev->ifindex); + err = 0; + if (IS_ERR(rth)) + err = PTR_ERR(rth); e_nobufs: return -ENOBUFS; @@ -2051,7 +2050,10 @@ static int ip_mkroute_input(struct sk_buff *skb, /* put it into the cache */ hash = rt_hash(daddr, saddr, fl->iif, rt_genid(dev_net(rth->dst.dev))); - return rt_intern_hash(hash, rth, NULL, skb, fl->iif); + rth = rt_intern_hash(hash, rth, skb, fl->iif); + if (IS_ERR(rth)) + return PTR_ERR(rth); + return 0; } /* @@ -2194,7 +2196,10 @@ local_input: } rth->rt_type = res.type; hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net)); - err = rt_intern_hash(hash, rth, NULL, skb, fl.iif); + rth = rt_intern_hash(hash, rth, skb, fl.iif); + err = 0; + if (IS_ERR(rth)) + err = PTR_ERR(rth); goto out; no_route: @@ -2422,8 +2427,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res, * called with rcu_read_lock(); */ -static int ip_route_output_slow(struct net *net, struct rtable **rp, - const struct flowi *oldflp) +static struct rtable *ip_route_output_slow(struct net *net, + const struct flowi *oldflp) { u32 tos = RT_FL_TOS(oldflp); struct flowi fl = { .fl4_dst = oldflp->fl4_dst, @@ -2438,8 +2443,6 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, unsigned int flags = 0; struct net_device *dev_out = NULL; struct rtable *rth; - int err; - res.fi = NULL; #ifdef CONFIG_IP_MULTIPLE_TABLES @@ -2448,7 +2451,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, rcu_read_lock(); if (oldflp->fl4_src) { - err = -EINVAL; + rth = ERR_PTR(-EINVAL); if (ipv4_is_multicast(oldflp->fl4_src) || ipv4_is_lbcast(oldflp->fl4_src) || ipv4_is_zeronet(oldflp->fl4_src)) @@ -2499,13 +2502,13 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, if (oldflp->oif) { dev_out = dev_get_by_index_rcu(net, oldflp->oif); - err = -ENODEV; + rth = ERR_PTR(-ENODEV); if (dev_out == NULL) goto out; /* RACE: Check return value of inet_select_addr instead. */ if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { - err = -ENETUNREACH; + rth = ERR_PTR(-ENETUNREACH); goto out; } if (ipv4_is_local_multicast(oldflp->fl4_dst) || @@ -2563,7 +2566,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, res.type = RTN_UNICAST; goto make_route; } - err = -ENETUNREACH; + rth = ERR_PTR(-ENETUNREACH); goto out; } @@ -2598,23 +2601,20 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, make_route: rth = __mkroute_output(&res, &fl, oldflp, dev_out, flags); - if (IS_ERR(rth)) - err = PTR_ERR(rth); - else { + if (!IS_ERR(rth)) { unsigned int hash; hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif, rt_genid(dev_net(dev_out))); - err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif); + rth = rt_intern_hash(hash, rth, NULL, oldflp->oif); } out: rcu_read_unlock(); - return err; + return rth; } -int __ip_route_output_key(struct net *net, struct rtable **rp, - const struct flowi *flp) +struct rtable *__ip_route_output_key(struct net *net, const struct flowi *flp) { struct rtable *rth; unsigned int hash; @@ -2639,15 +2639,14 @@ int __ip_route_output_key(struct net *net, struct rtable **rp, dst_use(&rth->dst, jiffies); RT_CACHE_STAT_INC(out_hit); rcu_read_unlock_bh(); - *rp = rth; - return 0; + return rth; } RT_CACHE_STAT_INC(out_hlist_search); } rcu_read_unlock_bh(); slow_output: - return ip_route_output_slow(net, rp, flp); + return ip_route_output_slow(net, flp); } EXPORT_SYMBOL_GPL(__ip_route_output_key); @@ -2717,34 +2716,29 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or return rt ? &rt->dst : ERR_PTR(-ENOMEM); } -int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp, - struct sock *sk) +struct rtable *ip_route_output_flow(struct net *net, struct flowi *flp, + struct sock *sk) { - int err; + struct rtable *rt = __ip_route_output_key(net, flp); - if ((err = __ip_route_output_key(net, rp, flp)) != 0) - return err; + if (IS_ERR(rt)) + return rt; if (flp->proto) { if (!flp->fl4_src) - flp->fl4_src = (*rp)->rt_src; + flp->fl4_src = rt->rt_src; if (!flp->fl4_dst) - flp->fl4_dst = (*rp)->rt_dst; - *rp = (struct rtable *) xfrm_lookup(net, &(*rp)->dst, flp, sk, 0); - if (IS_ERR(*rp)) { - err = PTR_ERR(*rp); - *rp = NULL; - return err; - } + flp->fl4_dst = rt->rt_dst; + rt = (struct rtable *) xfrm_lookup(net, &rt->dst, flp, sk, 0); } - return 0; + return rt; } EXPORT_SYMBOL_GPL(ip_route_output_flow); -int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp) +struct rtable *ip_route_output_key(struct net *net, struct flowi *flp) { - return ip_route_output_flow(net, rp, flp, NULL); + return ip_route_output_flow(net, flp, NULL); } EXPORT_SYMBOL(ip_route_output_key); @@ -2915,7 +2909,11 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, .mark = mark, }; - err = ip_route_output_key(net, &rt, &fl); + rt = ip_route_output_key(net, &fl); + + err = 0; + if (IS_ERR(rt)) + err = PTR_ERR(rt); } if (err) -- cgit v1.2.3-70-g09d2