xfrm: Return dst directly from xfrm_lookup()

Instead of on the stack.

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

14 files changed, 111 insertions, 89 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 8948452132ad..2a46cbaef92d 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -426,15 +426,17 @@ enum {
 
 struct flowi;
 #ifndef CONFIG_XFRM
-static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                              const struct flowi *fl, struct sock *sk,
-                              int flags)
+static inline struct dst_entry *xfrm_lookup(struct net *net,
+                                            struct dst_entry *dst_orig,
+                                            const struct flowi *fl, struct sock *sk,
+                                            int flags)
 {
-        return 0;
+        return dst_orig;
 } 
 #else
-extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                       const struct flowi *fl, struct sock *sk, int flags);
+extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
+                                     const struct flowi *fl, struct sock *sk,
+                                     int flags);
 #endif
 #endif
 
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 0877147d2167..484fdbf92bd8 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1222,7 +1222,11 @@ static int dn_route_output_key(struct dst_entry **pprt, struct flowi *flp, int f
 
         err = __dn_route_output_key(pprt, flp, flags);
         if (err == 0 && flp->proto) {
-                err = xfrm_lookup(&init_net, pprt, flp, NULL, 0);
+                *pprt = xfrm_lookup(&init_net, *pprt, flp, NULL, 0);
+                if (IS_ERR(*pprt)) {
+                        err = PTR_ERR(*pprt);
+                        *pprt = NULL;
+                }
         }
         return err;
 }
@@ -1235,7 +1239,11 @@ int dn_route_output_sock(struct dst_entry **pprt, struct flowi *fl, struct sock
         if (err == 0 && fl->proto) {
                 if (!(flags & MSG_DONTWAIT))
                         fl->flags |= FLOWI_FLAG_CAN_SLEEP;
-                err = xfrm_lookup(&init_net, pprt, fl, sk, 0);
+                *pprt = xfrm_lookup(&init_net, *pprt, fl, sk, 0);
+                if (IS_ERR(*pprt)) {
+                        err = PTR_ERR(*pprt);
+                        *pprt = NULL;
+                }
         }
         return err;
 }
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 2a86c8951dcd..c23bd8cdeee0 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -398,18 +398,14 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
         if (!fl.fl4_src)
                 fl.fl4_src = rt->rt_src;
 
-        err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0);
-        switch (err) {
-        case 0:
+        rt = (struct rtable *) xfrm_lookup(net, &rt->dst, &fl, NULL, 0);
+        if (!IS_ERR(rt)) {
                 if (rt != rt2)
                         return rt;
-                break;
-        case -EPERM:
+        } else if (PTR_ERR(rt) == -EPERM) {
                 rt = NULL;
-                break;
-        default:
-                return ERR_PTR(err);
-        }
+        } else
+                return rt;
 
         err = xfrm_decode_session_reverse(skb_in, &fl, AF_INET);
         if (err)
@@ -438,22 +434,18 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
         if (err)
                 goto relookup_failed;
 
-        err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL,
-                          XFRM_LOOKUP_ICMP);
-        switch (err) {
-        case 0:
+        rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, &fl, NULL, XFRM_LOOKUP_ICMP);
+        if (!IS_ERR(rt2)) {
                 dst_release(&rt->dst);
                 rt = rt2;
-                break;
-        case -EPERM:
-                return ERR_PTR(err);
-        default:
-                if (!rt)
-                        return ERR_PTR(err);
-                break;
+        } else if (PTR_ERR(rt2) == -EPERM) {
+                if (rt)
+                        dst_release(&rt->dst);
+                return rt2;
+        } else {
+                err = PTR_ERR(rt2);
+                goto relookup_failed;
         }
-
-
         return rt;
 
 relookup_failed:
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 994a1f29ebbc..9770bb427952 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -69,7 +69,8 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
             xfrm_decode_session(skb, &fl, AF_INET) == 0) {
                 struct dst_entry *dst = skb_dst(skb);
                 skb_dst_set(skb, NULL);
-                if (xfrm_lookup(net, &dst, &fl, skb->sk, 0))
+                dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
+                if (IS_ERR(dst))
                         return -1;
                 skb_dst_set(skb, dst);
         }
@@ -102,7 +103,8 @@ int ip_xfrm_me_harder(struct sk_buff *skb)
                 dst = ((struct xfrm_dst *)dst)->route;
         dst_hold(dst);
 
-        if (xfrm_lookup(dev_net(dst->dev), &dst, &fl, skb->sk, 0) < 0)
+        dst = xfrm_lookup(dev_net(dst->dev), dst, &fl, skb->sk, 0);
+        if (IS_ERR(dst))
                 return -1;
 
         skb_dst_drop(skb);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e24e4cf2a112..63d37004ee66 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2730,7 +2730,12 @@ int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
                         flp->fl4_src = (*rp)->rt_src;
                 if (!flp->fl4_dst)
                         flp->fl4_dst = (*rp)->rt_dst;
-                return xfrm_lookup(net, (struct dst_entry **)rp, flp, sk, 0);
+                *rp = (struct rtable *) xfrm_lookup(net, &(*rp)->dst, flp, sk, 0);
+                if (IS_ERR(*rp)) {
+                        err = PTR_ERR(*rp);
+                        *rp = NULL;
+                        return err;
+                }
         }
 
         return 0;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index e332bae104ee..55665956b3a8 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -324,17 +324,15 @@ static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *sk
         /* No need to clone since we're just using its address. */
         dst2 = dst;
 
-        err = xfrm_lookup(net, &dst, fl, sk, 0);
-        switch (err) {
-        case 0:
+        dst = xfrm_lookup(net, dst, fl, sk, 0);
+        if (!IS_ERR(dst)) {
                 if (dst != dst2)
                         return dst;
-                break;
-        case -EPERM:
-                dst = NULL;
-                break;
-        default:
-                return ERR_PTR(err);
+        } else {
+                if (PTR_ERR(dst) == -EPERM)
+                        dst = NULL;
+                else
+                        return dst;
         }
 
         err = xfrm_decode_session_reverse(skb, &fl2, AF_INET6);
@@ -345,17 +343,17 @@ static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *sk
         if (err)
                 goto relookup_failed;
 
-        err = xfrm_lookup(net, &dst2, &fl2, sk, XFRM_LOOKUP_ICMP);
-        switch (err) {
-        case 0:
+        dst2 = xfrm_lookup(net, dst2, &fl2, sk, XFRM_LOOKUP_ICMP);
+        if (!IS_ERR(dst2)) {
                 dst_release(dst);
                 dst = dst2;
-                break;
-        case -EPERM:
-                dst_release(dst);
-                return ERR_PTR(err);
-        default:
-                goto relookup_failed;
+        } else {
+                err = PTR_ERR(dst2);
+                if (err == -EPERM) {
+                        dst_release(dst);
+                        return dst2;
+                } else
+                        goto relookup_failed;
         }
 
 relookup_failed:
@@ -560,7 +558,8 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
         err = ip6_dst_lookup(sk, &dst, &fl);
         if (err)
                 goto out;
-        if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0)
+        dst = xfrm_lookup(net, dst, &fl, sk, 0);
+        if (IS_ERR(dst))
                 goto out;
 
         if (ipv6_addr_is_multicast(&fl.fl6_dst))
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 35a4ad90a0f5..adaffaf84555 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1028,10 +1028,7 @@ struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi *fl,
         if (can_sleep)
                 fl->flags |= FLOWI_FLAG_CAN_SLEEP;
 
-        err = xfrm_lookup(sock_net(sk), &dst, fl, sk, 0);
-        if (err)
-                return ERR_PTR(err);
-        return dst;
+        return xfrm_lookup(sock_net(sk), dst, fl, sk, 0);
 }
 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
 
@@ -1067,10 +1064,7 @@ struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi *fl,
         if (can_sleep)
                 fl->flags |= FLOWI_FLAG_CAN_SLEEP;
 
-        err = xfrm_lookup(sock_net(sk), &dst, fl, sk, 0);
-        if (err)
-                return ERR_PTR(err);
-        return dst;
+        return xfrm_lookup(sock_net(sk), dst, fl, sk, 0);
 }
 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
 
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 4f4483e697bd..da43038ae18e 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -903,8 +903,14 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
         else {
                 dst = ip6_route_output(net, NULL, fl);
 
-                if (dst->error || xfrm_lookup(net, &dst, fl, NULL, 0) < 0)
+                if (dst->error)
                         goto tx_err_link_failure;
+                dst = xfrm_lookup(net, dst, fl, NULL, 0);
+                if (IS_ERR(dst)) {
+                        err = PTR_ERR(dst);
+                        dst = NULL;
+                        goto tx_err_link_failure;
+                }
         }
 
         tdev = dst->dev;
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 49f986d626a0..7b27d08ee281 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1429,7 +1429,12 @@ static void mld_sendpack(struct sk_buff *skb)
                          &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
                          skb->dev->ifindex);
 
-        err = xfrm_lookup(net, &dst, &fl, NULL, 0);
+        dst = xfrm_lookup(net, dst, &fl, NULL, 0);
+        err = 0;
+        if (IS_ERR(dst)) {
+                err = PTR_ERR(dst);
+                dst = NULL;
+        }
         skb_dst_set(skb, dst);
         if (err)
                 goto err_out;
@@ -1796,9 +1801,11 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
                          &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
                          skb->dev->ifindex);
 
-        err = xfrm_lookup(net, &dst, &fl, NULL, 0);
-        if (err)
+        dst = xfrm_lookup(net, dst, &fl, NULL, 0);
+        if (IS_ERR(dst)) {
+                err = PTR_ERR(dst);
                 goto err_out;
+        }
 
         skb_dst_set(skb, dst);
         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, skb->dev,
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 7254ce364006..9360d3be94f0 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -529,8 +529,8 @@ void ndisc_send_skb(struct sk_buff *skb,
                 return;
         }
 
-        err = xfrm_lookup(net, &dst, &fl, NULL, 0);
-        if (err < 0) {
+        dst = xfrm_lookup(net, dst, &fl, NULL, 0);
+        if (IS_ERR(dst)) {
                 kfree_skb(skb);
                 return;
         }
@@ -1542,8 +1542,8 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
         if (dst == NULL)
                 return;
 
-        err = xfrm_lookup(net, &dst, &fl, NULL, 0);
-        if (err)
+        dst = xfrm_lookup(net, dst, &fl, NULL, 0);
+        if (IS_ERR(dst))
                 return;
 
         rt = (struct rt6_info *) dst;
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 35915e8617f0..8d74116ae27d 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -39,7 +39,8 @@ int ip6_route_me_harder(struct sk_buff *skb)
         if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
             xfrm_decode_session(skb, &fl, AF_INET6) == 0) {
                 skb_dst_set(skb, NULL);
-                if (xfrm_lookup(net, &dst, &fl, skb->sk, 0))
+                dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
+                if (IS_ERR(dst))
                         return -1;
                 skb_dst_set(skb, dst);
         }
diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index bf998feac14e..91f6a61cefab 100644
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -101,7 +101,8 @@ static void send_reset(struct net *net, struct sk_buff *oldskb)
                 dst_release(dst);
                 return;
         }
-        if (xfrm_lookup(net, &dst, &fl, NULL, 0))
+        dst = xfrm_lookup(net, dst, &fl, NULL, 0);
+        if (IS_ERR(dst))
                 return;
 
         hh_len = (dst->dev->hard_header_len + 15)&~15;
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index a48239aba33b..6264219f0a42 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -218,8 +218,13 @@ __ip_vs_route_output_v6(struct net *net, struct in6_addr *daddr,
             ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
                                &fl.fl6_dst, 0, &fl.fl6_src) < 0)
                 goto out_err;
-        if (do_xfrm && xfrm_lookup(net, &dst, &fl, NULL, 0) < 0)
-                goto out_err;
+        if (do_xfrm) {
+                dst = xfrm_lookup(net, dst, &fl, NULL, 0);
+                if (IS_ERR(dst)) {
+                        dst = NULL;
+                        goto out_err;
+                }
+        }
         ipv6_addr_copy(ret_saddr, &fl.fl6_src);
         return dst;
 
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 0248afa11cda..b1932a629ef8 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1757,14 +1757,14 @@ static struct dst_entry *make_blackhole(struct net *net, u16 family,
  * At the moment we eat a raw IP route. Mostly to speed up lookups
  * on interfaces with disabled IPsec.
  */
-int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                const struct flowi *fl,
-                struct sock *sk, int flags)
+struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
+                              const struct flowi *fl,
+                              struct sock *sk, int flags)
 {
         struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
         struct flow_cache_object *flo;
         struct xfrm_dst *xdst;
-        struct dst_entry *dst, *dst_orig = *dst_p, *route;
+        struct dst_entry *dst, *route;
         u16 family = dst_orig->ops->family;
         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
@@ -1847,11 +1847,7 @@ restart:
                         xfrm_pols_put(pols, drop_pols);
                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
 
-                        dst = make_blackhole(net, family, dst_orig);
-                        if (IS_ERR(dst))
-                                return PTR_ERR(dst);
-                        *dst_p = dst;
-                        return 0;
+                        return make_blackhole(net, family, dst_orig);
                 }
                 if (fl->flags & FLOWI_FLAG_CAN_SLEEP) {
                         DECLARE_WAITQUEUE(wait, current);
@@ -1895,27 +1891,28 @@ no_transform:
                 goto error;
         } else if (num_xfrms > 0) {
                 /* Flow transformed */
-                *dst_p = dst;
                 dst_release(dst_orig);
         } else {
                 /* Flow passes untransformed */
                 dst_release(dst);
+                dst = dst_orig;
         }
 ok:
         xfrm_pols_put(pols, drop_pols);
-        return 0;
+        return dst;
 
 nopol:
-        if (!(flags & XFRM_LOOKUP_ICMP))
+        if (!(flags & XFRM_LOOKUP_ICMP)) {
+                dst = dst_orig;
                 goto ok;
+        }
         err = -ENOENT;
 error:
         dst_release(dst);
 dropdst:
         dst_release(dst_orig);
-        *dst_p = NULL;
         xfrm_pols_put(pols, drop_pols);
-        return err;
+        return ERR_PTR(err);
 }
 EXPORT_SYMBOL(xfrm_lookup);
 
@@ -2175,7 +2172,7 @@ int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
         struct net *net = dev_net(skb->dev);
         struct flowi fl;
         struct dst_entry *dst;
-        int res;
+        int res = 0;
 
         if (xfrm_decode_session(skb, &fl, family) < 0) {
                 XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
@@ -2183,9 +2180,12 @@ int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
         }
 
         skb_dst_force(skb);
-        dst = skb_dst(skb);
 
-        res = xfrm_lookup(net, &dst, &fl, NULL, 0) == 0;
+        dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, 0);
+        if (IS_ERR(dst)) {
+                res = 1;
+                dst = NULL;
+        }
         skb_dst_set(skb, dst);
         return res;
 }