ipv4: Make output route lookup return rtable directly.

Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>

17 files changed, 160 insertions, 138 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 44513bb8ac2e..35a502055018 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1101,23 +1101,20 @@ int sysctl_ip_dynaddr __read_mostly;
 static int inet_sk_reselect_saddr(struct sock *sk)
 {
         struct inet_sock *inet = inet_sk(sk);
-        int err;
-        struct rtable *rt;
         __be32 old_saddr = inet->inet_saddr;
-        __be32 new_saddr;
         __be32 daddr = inet->inet_daddr;
+        struct rtable *rt;
+        __be32 new_saddr;
 
         if (inet->opt && inet->opt->srr)
                 daddr = inet->opt->faddr;
 
         /* Query new route. */
-        err = ip_route_connect(&rt, daddr, 0,
-                               RT_CONN_FLAGS(sk),
-                               sk->sk_bound_dev_if,
-                               sk->sk_protocol,
-                               inet->inet_sport, inet->inet_dport, sk, false);
-        if (err)
-                return err;
+        rt = ip_route_connect(daddr, 0, RT_CONN_FLAGS(sk),
+                              sk->sk_bound_dev_if, sk->sk_protocol,
+                              inet->inet_sport, inet->inet_dport, sk, false);
+        if (IS_ERR(rt))
+                return PTR_ERR(rt);
 
         sk_setup_caps(sk, &rt->dst);
 
@@ -1160,7 +1157,7 @@ int inet_sk_rebuild_header(struct sock *sk)
         daddr = inet->inet_daddr;
         if (inet->opt && inet->opt->srr)
                 daddr = inet->opt->faddr;
-{
+        {
         struct flowi fl = {
                 .oif = sk->sk_bound_dev_if,
                 .mark = sk->sk_mark,
@@ -1174,11 +1171,14 @@ int inet_sk_rebuild_header(struct sock *sk)
         };
 
         security_sk_classify_flow(sk, &fl);
-        err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk);
-}
-        if (!err)
+        rt = ip_route_output_flow(sock_net(sk), &fl, sk);
+        }
+        if (!IS_ERR(rt)) {
+                err = 0;
                 sk_setup_caps(sk, &rt->dst);
-        else {
+        } else {
+                err = PTR_ERR(rt);
+
                 /* Routing failed... */
                 sk->sk_route_caps = 0;
                 /*
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 7927589813b5..fa9988da1da4 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -440,7 +440,8 @@ static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
         /*unsigned long now; */
         struct net *net = dev_net(dev);
 
-        if (ip_route_output_key(net, &rt, &fl) < 0)
+        rt = ip_route_output_key(net, &fl);
+        if (IS_ERR(rt))
                 return 1;
         if (rt->dst.dev != dev) {
                 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER);
@@ -1063,10 +1064,10 @@ static int arp_req_set(struct net *net, struct arpreq *r,
         if (dev == NULL) {
                 struct flowi fl = { .fl4_dst = ip,
                                     .fl4_tos = RTO_ONLINK };
-                struct rtable *rt;
-                err = ip_route_output_key(net, &rt, &fl);
-                if (err != 0)
-                        return err;
+                struct rtable *rt = ip_route_output_key(net, &fl);
+
+                if (IS_ERR(rt))
+                        return PTR_ERR(rt);
                 dev = rt->dst.dev;
                 ip_rt_put(rt);
                 if (!dev)
@@ -1177,7 +1178,6 @@ static int arp_req_delete_public(struct net *net, struct arpreq *r,
 static int arp_req_delete(struct net *net, struct arpreq *r,
                           struct net_device *dev)
 {
-        int err;
         __be32 ip;
 
         if (r->arp_flags & ATF_PUBL)
@@ -1187,10 +1187,9 @@ static int arp_req_delete(struct net *net, struct arpreq *r,
         if (dev == NULL) {
                 struct flowi fl = { .fl4_dst = ip,
                                     .fl4_tos = RTO_ONLINK };
-                struct rtable *rt;
-                err = ip_route_output_key(net, &rt, &fl);
-                if (err != 0)
-                        return err;
+                struct rtable *rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
+                        return PTR_ERR(rt);
                 dev = rt->dst.dev;
                 ip_rt_put(rt);
                 if (!dev)
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index eaee1edd2dd7..85bd24ca4f6d 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -46,11 +46,12 @@ int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
                 if (!saddr)
                         saddr = inet->mc_addr;
         }
-        err = ip_route_connect(&rt, usin->sin_addr.s_addr, saddr,
-                               RT_CONN_FLAGS(sk), oif,
-                               sk->sk_protocol,
-                               inet->inet_sport, usin->sin_port, sk, true);
-        if (err) {
+        rt = ip_route_connect(usin->sin_addr.s_addr, saddr,
+                              RT_CONN_FLAGS(sk), oif,
+                              sk->sk_protocol,
+                              inet->inet_sport, usin->sin_port, sk, true);
+        if (IS_ERR(rt)) {
+                err = PTR_ERR(rt);
                 if (err == -ENETUNREACH)
                         IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
                 return err;
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index c23bd8cdeee0..994a785d98f9 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -358,7 +358,8 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
                                     .fl4_tos = RT_TOS(ip_hdr(skb)->tos),
                                     .proto = IPPROTO_ICMP };
                 security_skb_classify_flow(skb, &fl);
-                if (ip_route_output_key(net, &rt, &fl))
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
                         goto out_unlock;
         }
         if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type,
@@ -388,9 +389,9 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
         int err;
 
         security_skb_classify_flow(skb_in, &fl);
-        err = __ip_route_output_key(net, &rt, &fl);
-        if (err)
-                return ERR_PTR(err);
+        rt = __ip_route_output_key(net, &fl);
+        if (IS_ERR(rt))
+                return rt;
 
         /* No need to clone since we're just using its address. */
         rt2 = rt;
@@ -412,15 +413,19 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
                 goto relookup_failed;
 
         if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL) {
-                err = __ip_route_output_key(net, &rt2, &fl);
+                rt2 = __ip_route_output_key(net, &fl);
+                if (IS_ERR(rt2))
+                        err = PTR_ERR(rt2);
         } else {
                 struct flowi fl2 = {};
                 unsigned long orefdst;
 
                 fl2.fl4_dst = fl.fl4_src;
-                err = ip_route_output_key(net, &rt2, &fl2);
-                if (err)
+                rt2 = ip_route_output_key(net, &fl2);
+                if (IS_ERR(rt2)) {
+                        err = PTR_ERR(rt2);
                         goto relookup_failed;
+                }
                 /* Ugh! */
                 orefdst = skb_in->_skb_refdst; /* save old refdst */
                 err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src,
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index e0e77e297de3..44ba9068b72f 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -325,7 +325,8 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
                 struct flowi fl = { .oif = dev->ifindex,
                                     .fl4_dst = IGMPV3_ALL_MCR,
                                     .proto = IPPROTO_IGMP };
-                if (ip_route_output_key(net, &rt, &fl)) {
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt)) {
                         kfree_skb(skb);
                         return NULL;
                 }
@@ -670,7 +671,8 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
                 struct flowi fl = { .oif = dev->ifindex,
                                     .fl4_dst = dst,
                                     .proto = IPPROTO_IGMP };
-                if (ip_route_output_key(net, &rt, &fl))
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
                         return -1;
         }
         if (rt->rt_src == 0) {
@@ -1440,7 +1442,6 @@ void ip_mc_destroy_dev(struct in_device *in_dev)
 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
 {
         struct flowi fl = { .fl4_dst = imr->imr_multiaddr.s_addr };
-        struct rtable *rt;
         struct net_device *dev = NULL;
         struct in_device *idev = NULL;
 
@@ -1454,9 +1455,12 @@ static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
                         return NULL;
         }
 
-        if (!dev && !ip_route_output_key(net, &rt, &fl)) {
-                dev = rt->dst.dev;
-                ip_rt_put(rt);
+        if (!dev) {
+                struct rtable *rt = ip_route_output_key(net, &fl);
+                if (!IS_ERR(rt)) {
+                        dev = rt->dst.dev;
+                        ip_rt_put(rt);
+                }
         }
         if (dev) {
                 imr->imr_ifindex = dev->ifindex;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 7f85d4aec26a..e4e301a61c5b 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -369,7 +369,8 @@ struct dst_entry *inet_csk_route_req(struct sock *sk,
         struct net *net = sock_net(sk);
 
         security_req_classify_flow(req, &fl);
-        if (ip_route_output_flow(net, &rt, &fl, sk))
+        rt = ip_route_output_flow(net, &fl, sk);
+        if (IS_ERR(rt))
                 goto no_route;
         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
                 goto route_err;
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 6613edfac28c..f9af98dd7561 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -778,7 +778,8 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
                         .proto = IPPROTO_GRE,
                         .fl_gre_key = tunnel->parms.o_key
                 };
-                if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
+                rt = ip_route_output_key(dev_net(dev), &fl);
+                if (IS_ERR(rt)) {
                         dev->stats.tx_carrier_errors++;
                         goto tx_error;
                 }
@@ -953,9 +954,9 @@ static int ipgre_tunnel_bind_dev(struct net_device *dev)
                         .proto = IPPROTO_GRE,
                         .fl_gre_key = tunnel->parms.o_key
                 };
-                struct rtable *rt;
+                struct rtable *rt = ip_route_output_key(dev_net(dev), &fl);
 
-                if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
+                if (!IS_ERR(rt)) {
                         tdev = rt->dst.dev;
                         ip_rt_put(rt);
                 }
@@ -1215,9 +1216,9 @@ static int ipgre_open(struct net_device *dev)
                         .proto = IPPROTO_GRE,
                         .fl_gre_key = t->parms.o_key
                 };
-                struct rtable *rt;
+                struct rtable *rt = ip_route_output_key(dev_net(dev), &fl);
 
-                if (ip_route_output_key(dev_net(dev), &rt, &fl))
+                if (IS_ERR(rt))
                         return -EADDRNOTAVAIL;
                 dev = rt->dst.dev;
                 ip_rt_put(rt);
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 33316b3534ca..171f483b21d5 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -355,7 +355,8 @@ int ip_queue_xmit(struct sk_buff *skb)
                          * itself out.
                          */
                         security_sk_classify_flow(sk, &fl);
-                        if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk))
+                        rt = ip_route_output_flow(sock_net(sk), &fl, sk);
+                        if (IS_ERR(rt))
                                 goto no_route;
                 }
                 sk_setup_caps(sk, &rt->dst);
@@ -1489,7 +1490,8 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
                                     .proto = sk->sk_protocol,
                                     .flags = ip_reply_arg_flowi_flags(arg) };
                 security_skb_classify_flow(skb, &fl);
-                if (ip_route_output_key(sock_net(sk), &rt, &fl))
+                rt = ip_route_output_key(sock_net(sk), &fl);
+                if (IS_ERR(rt))
                         return;
         }
 
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 988f52fba54a..e1e17576baa6 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -469,7 +469,8 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
                         .proto = IPPROTO_IPIP
                 };
 
-                if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
+                rt = ip_route_output_key(dev_net(dev), &fl);
+                if (IS_ERR(rt)) {
                         dev->stats.tx_carrier_errors++;
                         goto tx_error_icmp;
                 }
@@ -590,9 +591,9 @@ static void ipip_tunnel_bind_dev(struct net_device *dev)
                         .fl4_tos = RT_TOS(iph->tos),
                         .proto = IPPROTO_IPIP
                 };
-                struct rtable *rt;
+                struct rtable *rt = ip_route_output_key(dev_net(dev), &fl);
 
-                if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
+                if (!IS_ERR(rt)) {
                         tdev = rt->dst.dev;
                         ip_rt_put(rt);
                 }
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 8b65a12654e7..26ca2f2d37ce 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1618,8 +1618,8 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
                         .fl4_tos = RT_TOS(iph->tos),
                         .proto = IPPROTO_IPIP
                 };
-
-                if (ip_route_output_key(net, &rt, &fl))
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
                         goto out_free;
                 encap = sizeof(struct iphdr);
         } else {
@@ -1629,8 +1629,8 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
                         .fl4_tos = RT_TOS(iph->tos),
                         .proto = IPPROTO_IPIP
                 };
-
-                if (ip_route_output_key(net, &rt, &fl))
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
                         goto out_free;
         }
 
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 9770bb427952..67bf709180de 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -38,7 +38,8 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
                 fl.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0;
                 fl.mark = skb->mark;
                 fl.flags = skb->sk ? inet_sk_flowi_flags(skb->sk) : 0;
-                if (ip_route_output_key(net, &rt, &fl) != 0)
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
                         return -1;
 
                 /* Drop old route. */
@@ -48,7 +49,8 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
                 /* non-local src, find valid iif to satisfy
                  * rp-filter when calling ip_route_input. */
                 fl.fl4_dst = iph->saddr;
-                if (ip_route_output_key(net, &rt, &fl) != 0)
+                rt = ip_route_output_key(net, &fl);
+                if (IS_ERR(rt))
                         return -1;
 
                 orefdst = skb->_skb_refdst;
@@ -221,7 +223,11 @@ static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
 
 static int nf_ip_route(struct dst_entry **dst, struct flowi *fl)
 {
-        return ip_route_output_key(&init_net, (struct rtable **)dst, fl);
+        struct rtable *rt = ip_route_output_key(&init_net, fl);
+        if (IS_ERR(rt))
+                return PTR_ERR(rt);
+        *dst = &rt->dst;
+        return 0;
 }
 
 static const struct nf_afinfo nf_ip_afinfo = {
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index d7a2d1eaec09..467d570d087a 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -564,10 +564,12 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                 }
 
                 security_sk_classify_flow(sk, &fl);
-                err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk);
+                rt = ip_route_output_flow(sock_net(sk), &fl, sk);
+                if (IS_ERR(rt)) {
+                        err = PTR_ERR(rt);
+                        goto done;
+                }
         }
-        if (err)
-                goto done;
 
         err = -EACCES;
         if (rt->rt_flags & RTCF_BROADCAST && !sock_flag(sk, SOCK_BROADCAST))
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 63d37004ee66..5090e956f6b8 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)
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 47519205a014..0ad6ddf638a7 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -355,7 +355,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
                                     .fl_ip_sport = th->dest,
                                     .fl_ip_dport = th->source };
                 security_req_classify_flow(req, &fl);
-                if (ip_route_output_key(sock_net(sk), &rt, &fl)) {
+                rt = ip_route_output_key(sock_net(sk), &fl);
+                if (IS_ERR(rt)) {
                         reqsk_free(req);
                         goto out;
                 }
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 05bc6d9455fc..f7e6c2c2d2bb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -152,7 +152,6 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         __be16 orig_sport, orig_dport;
         struct rtable *rt;
         __be32 daddr, nexthop;
-        int tmp;
         int err;
 
         if (addr_len < sizeof(struct sockaddr_in))
@@ -170,14 +169,15 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 
         orig_sport = inet->inet_sport;
         orig_dport = usin->sin_port;
-        tmp = ip_route_connect(&rt, nexthop, inet->inet_saddr,
-                               RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
-                               IPPROTO_TCP,
-                               orig_sport, orig_dport, sk, true);
-        if (tmp < 0) {
-                if (tmp == -ENETUNREACH)
+        rt = ip_route_connect(nexthop, inet->inet_saddr,
+                              RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
+                              IPPROTO_TCP,
+                              orig_sport, orig_dport, sk, true);
+        if (IS_ERR(rt)) {
+                err = PTR_ERR(rt);
+                if (err == -ENETUNREACH)
                         IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
-                return tmp;
+                return err;
         }
 
         if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
@@ -236,12 +236,14 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         if (err)
                 goto failure;
 
-        err = ip_route_newports(&rt, IPPROTO_TCP,
-                                orig_sport, orig_dport,
-                                inet->inet_sport, inet->inet_dport, sk);
-        if (err)
+        rt = ip_route_newports(rt, IPPROTO_TCP,
+                               orig_sport, orig_dport,
+                               inet->inet_sport, inet->inet_dport, sk);
+        if (IS_ERR(rt)) {
+                err = PTR_ERR(rt);
+                rt = NULL;
                 goto failure;
-
+        }
         /* OK, now commit destination to socket.  */
         sk->sk_gso_type = SKB_GSO_TCPV4;
         sk_setup_caps(sk, &rt->dst);
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ed9a5b7bee53..95e0c2c194a1 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -922,8 +922,9 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                 struct net *net = sock_net(sk);
 
                 security_sk_classify_flow(sk, &fl);
-                err = ip_route_output_flow(net, &rt, &fl, sk);
-                if (err) {
+                rt = ip_route_output_flow(net, &fl, sk);
+                if (IS_ERR(rt)) {
+                        err = PTR_ERR(rt);
                         if (err == -ENETUNREACH)
                                 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
                         goto out;
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 5f0f058dc376..45b821480427 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -26,18 +26,16 @@ static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
                 .fl4_dst = daddr->a4,
                 .fl4_tos = tos,
         };
-        struct dst_entry *dst;
         struct rtable *rt;
-        int err;
 
         if (saddr)
                 fl.fl4_src = saddr->a4;
 
-        err = __ip_route_output_key(net, &rt, &fl);
-        dst = &rt->dst;
-        if (err)
-                dst = ERR_PTR(err);
-        return dst;
+        rt = __ip_route_output_key(net, &fl);
+        if (!IS_ERR(rt))
+                return &rt->dst;
+
+        return ERR_CAST(rt);
 }
 
 static int xfrm4_get_saddr(struct net *net,