net: Make dst_alloc() take more explicit initializations.

Now the dst->dev, dev->obsolete, and dst->flags values can
be specified as well.

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

5 files changed, 42 insertions, 60 deletions

diff --git a/net/core/dst.c b/net/core/dst.c
index 91104d35de7d..9505778ec800 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -166,7 +166,8 @@ EXPORT_SYMBOL(dst_discard);
 
 const u32 dst_default_metrics[RTAX_MAX];
 
-void *dst_alloc(struct dst_ops *ops, int initial_ref)
+void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
+                int initial_ref, int initial_obsolete, int flags)
 {
         struct dst_entry *dst;
 
@@ -177,12 +178,19 @@ void *dst_alloc(struct dst_ops *ops, int initial_ref)
         dst = kmem_cache_zalloc(ops->kmem_cachep, GFP_ATOMIC);
         if (!dst)
                 return NULL;
-        atomic_set(&dst->__refcnt, initial_ref);
         dst->ops = ops;
-        dst->lastuse = jiffies;
-        dst->path = dst;
-        dst->input = dst->output = dst_discard;
+        dst->dev = dev;
+        if (dev)
+                dev_hold(dev);
         dst_init_metrics(dst, dst_default_metrics, true);
+        dst->path = dst;
+        dst->input = dst_discard;
+        dst->output = dst_discard;
+
+        dst->obsolete = initial_obsolete;
+        atomic_set(&dst->__refcnt, initial_ref);
+        dst->lastuse = jiffies;
+        dst->flags = flags;
 #if RT_CACHE_DEBUG >= 2
         atomic_inc(&dst_total);
 #endif
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 9f09d4fc2880..f489b081c25d 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1125,13 +1125,10 @@ make_route:
         if (dev_out->flags & IFF_LOOPBACK)
                 flags |= RTCF_LOCAL;
 
-        rt = dst_alloc(&dn_dst_ops, 0);
+        rt = dst_alloc(&dn_dst_ops, dev_out, 1, 0, DST_HOST);
         if (rt == NULL)
                 goto e_nobufs;
 
-        atomic_set(&rt->dst.__refcnt, 1);
-        rt->dst.flags   = DST_HOST;
-
         rt->fld.saddr        = oldflp->saddr;
         rt->fld.daddr        = oldflp->daddr;
         rt->fld.flowidn_oif  = oldflp->flowidn_oif;
@@ -1146,8 +1143,6 @@ make_route:
         rt->rt_dst_map    = fld.daddr;
         rt->rt_src_map    = fld.saddr;
 
-        rt->dst.dev = dev_out;
-        dev_hold(dev_out);
         rt->dst.neighbour = neigh;
         neigh = NULL;
 
@@ -1399,7 +1394,7 @@ static int dn_route_input_slow(struct sk_buff *skb)
         }
 
 make_route:
-        rt = dst_alloc(&dn_dst_ops, 0);
+        rt = dst_alloc(&dn_dst_ops, out_dev, 0, 0, DST_HOST);
         if (rt == NULL)
                 goto e_nobufs;
 
@@ -1419,9 +1414,7 @@ make_route:
         rt->fld.flowidn_iif  = in_dev->ifindex;
         rt->fld.flowidn_mark = fld.flowidn_mark;
 
-        rt->dst.flags = DST_HOST;
         rt->dst.neighbour = neigh;
-        rt->dst.dev = out_dev;
         rt->dst.lastuse = jiffies;
         rt->dst.output = dn_rt_bug;
         switch(res.type) {
@@ -1440,8 +1433,6 @@ make_route:
                         rt->dst.input = dst_discard;
         }
         rt->rt_flags = flags;
-        if (rt->dst.dev)
-                dev_hold(rt->dst.dev);
 
         err = dn_rt_set_next_hop(rt, &res);
         if (err)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index d63f780c6941..b471d89b57ee 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1833,17 +1833,13 @@ static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *oldflp4,
         rt->rt_type = type;
 }
 
-static struct rtable *rt_dst_alloc(bool nopolicy, bool noxfrm)
+static struct rtable *rt_dst_alloc(struct net_device *dev,
+                                   bool nopolicy, bool noxfrm)
 {
-        struct rtable *rt = dst_alloc(&ipv4_dst_ops, 1);
-        if (rt) {
-                rt->dst.obsolete = -1;
-
-                rt->dst.flags = DST_HOST |
-                        (nopolicy ? DST_NOPOLICY : 0) |
-                        (noxfrm ? DST_NOXFRM : 0);
-        }
-        return rt;
+        return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
+                         DST_HOST |
+                         (nopolicy ? DST_NOPOLICY : 0) |
+                         (noxfrm ? DST_NOXFRM : 0));
 }
 
 /* called in rcu_read_lock() section */
@@ -1876,7 +1872,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
                 if (err < 0)
                         goto e_err;
         }
-        rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
+        rth = rt_dst_alloc(init_net.loopback_dev,
+                           IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
         if (!rth)
                 goto e_nobufs;
 
@@ -1893,8 +1890,6 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 #endif
         rth->rt_route_iif = dev->ifindex;
         rth->rt_iif     = dev->ifindex;
-        rth->dst.dev    = init_net.loopback_dev;
-        dev_hold(rth->dst.dev);
         rth->rt_oif     = 0;
         rth->rt_gateway = daddr;
         rth->rt_spec_dst= spec_dst;
@@ -2013,7 +2008,8 @@ static int __mkroute_input(struct sk_buff *skb,
                 }
         }
 
-        rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
+        rth = rt_dst_alloc(out_dev->dev,
+                           IN_DEV_CONF_GET(in_dev, NOPOLICY),
                            IN_DEV_CONF_GET(out_dev, NOXFRM));
         if (!rth) {
                 err = -ENOBUFS;
@@ -2029,8 +2025,6 @@ static int __mkroute_input(struct sk_buff *skb,
         rth->rt_gateway = daddr;
         rth->rt_route_iif = in_dev->dev->ifindex;
         rth->rt_iif     = in_dev->dev->ifindex;
-        rth->dst.dev    = (out_dev)->dev;
-        dev_hold(rth->dst.dev);
         rth->rt_oif     = 0;
         rth->rt_spec_dst= spec_dst;
 
@@ -2188,7 +2182,8 @@ brd_input:
         RT_CACHE_STAT_INC(in_brd);
 
 local_input:
-        rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
+        rth = rt_dst_alloc(net->loopback_dev,
+                           IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
         if (!rth)
                 goto e_nobufs;
 
@@ -2206,8 +2201,6 @@ local_input:
 #endif
         rth->rt_route_iif = dev->ifindex;
         rth->rt_iif     = dev->ifindex;
-        rth->dst.dev    = net->loopback_dev;
-        dev_hold(rth->dst.dev);
         rth->rt_gateway = daddr;
         rth->rt_spec_dst= spec_dst;
         rth->dst.input= ip_local_deliver;
@@ -2392,7 +2385,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
                         fi = NULL;
         }
 
-        rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
+        rth = rt_dst_alloc(dev_out,
+                           IN_DEV_CONF_GET(in_dev, NOPOLICY),
                            IN_DEV_CONF_GET(in_dev, NOXFRM));
         if (!rth)
                 return ERR_PTR(-ENOBUFS);
@@ -2406,10 +2400,6 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
         rth->rt_src     = fl4->saddr;
         rth->rt_route_iif = 0;
         rth->rt_iif     = oldflp4->flowi4_oif ? : dev_out->ifindex;
-        /* get references to the devices that are to be hold by the routing
-           cache entry */
-        rth->dst.dev    = dev_out;
-        dev_hold(dev_out);
         rth->rt_gateway = fl4->daddr;
         rth->rt_spec_dst= fl4->saddr;
 
@@ -2711,7 +2701,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = {
 
 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
 {
-        struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, 1);
+        struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
         struct rtable *ort = (struct rtable *) dst_orig;
 
         if (rt) {
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 19a77d0e0308..e8b2bb9060ef 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -227,9 +227,10 @@ static struct rt6_info ip6_blk_hole_entry_template = {
 #endif
 
 /* allocate dst with ip6_dst_ops */
-static inline struct rt6_info *ip6_dst_alloc(struct dst_ops *ops)
+static inline struct rt6_info *ip6_dst_alloc(struct dst_ops *ops,
+                                             struct net_device *dev)
 {
-        return (struct rt6_info *)dst_alloc(ops, 0);
+        return (struct rt6_info *)dst_alloc(ops, dev, 0, 0, 0);
 }
 
 static void ip6_dst_destroy(struct dst_entry *dst)
@@ -881,10 +882,10 @@ EXPORT_SYMBOL(ip6_route_output);
 
 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
 {
-        struct rt6_info *rt = dst_alloc(&ip6_dst_blackhole_ops, 1);
-        struct rt6_info *ort = (struct rt6_info *) dst_orig;
+        struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
         struct dst_entry *new = NULL;
 
+        rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, 0, 0);
         if (rt) {
                 new = &rt->dst;
 
@@ -893,9 +894,6 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
                 new->output = dst_discard;
 
                 dst_copy_metrics(new, &ort->dst);
-                new->dev = ort->dst.dev;
-                if (new->dev)
-                        dev_hold(new->dev);
                 rt->rt6i_idev = ort->rt6i_idev;
                 if (rt->rt6i_idev)
                         in6_dev_hold(rt->rt6i_idev);
@@ -1038,13 +1036,12 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
         if (unlikely(idev == NULL))
                 return NULL;
 
-        rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
+        rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops, dev);
         if (unlikely(rt == NULL)) {
                 in6_dev_put(idev);
                 goto out;
         }
 
-        dev_hold(dev);
         if (neigh)
                 neigh_hold(neigh);
         else {
@@ -1053,7 +1050,6 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
                         neigh = NULL;
         }
 
-        rt->rt6i_dev      = dev;
         rt->rt6i_idev     = idev;
         rt->rt6i_nexthop  = neigh;
         atomic_set(&rt->dst.__refcnt, 1);
@@ -1212,7 +1208,7 @@ int ip6_route_add(struct fib6_config *cfg)
                 goto out;
         }
 
-        rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
+        rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops, NULL);
 
         if (rt == NULL) {
                 err = -ENOMEM;
@@ -1731,7 +1727,8 @@ void rt6_pmtu_discovery(const struct in6_addr *daddr, const struct in6_addr *sad
 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)
 {
         struct net *net = dev_net(ort->rt6i_dev);
-        struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
+        struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops,
+                                            ort->dst.dev);
 
         if (rt) {
                 rt->dst.input = ort->dst.input;
@@ -1739,9 +1736,6 @@ static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)
 
                 dst_copy_metrics(&rt->dst, &ort->dst);
                 rt->dst.error = ort->dst.error;
-                rt->dst.dev = ort->dst.dev;
-                if (rt->dst.dev)
-                        dev_hold(rt->dst.dev);
                 rt->rt6i_idev = ort->rt6i_idev;
                 if (rt->rt6i_idev)
                         in6_dev_hold(rt->rt6i_idev);
@@ -2011,7 +2005,8 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
                                     int anycast)
 {
         struct net *net = dev_net(idev->dev);
-        struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
+        struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops,
+                                            net->loopback_dev);
         struct neighbour *neigh;
 
         if (rt == NULL) {
@@ -2021,13 +2016,11 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
                 return ERR_PTR(-ENOMEM);
         }
 
-        dev_hold(net->loopback_dev);
         in6_dev_hold(idev);
 
         rt->dst.flags = DST_HOST;
         rt->dst.input = ip6_input;
         rt->dst.output = ip6_output;
-        rt->rt6i_dev = net->loopback_dev;
         rt->rt6i_idev = idev;
         rt->dst.obsolete = -1;
 
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 15792d8b6272..70552c4e2272 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1348,7 +1348,7 @@ static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
         default:
                 BUG();
         }
-        xdst = dst_alloc(dst_ops, 0);
+        xdst = dst_alloc(dst_ops, NULL, 0, 0, 0);
         xfrm_policy_put_afinfo(afinfo);
 
         if (likely(xdst))