ipv4: Use caller's on-stack flowi as-is in output route lookups.

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

1 files changed, 80 insertions, 78 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index fb9211adf079..93f71be1d5d1 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1767,7 +1767,7 @@ static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
         return mtu;
 }
 
-static void rt_init_metrics(struct rtable *rt, const struct flowi4 *oldflp4,
+static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
                             struct fib_info *fi)
 {
         struct inet_peer *peer;
@@ -1776,7 +1776,7 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *oldflp4,
         /* If a peer entry exists for this destination, we must hook
          * it up in order to get at cached metrics.
          */
-        if (oldflp4 && (oldflp4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
+        if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
                 create = 1;
 
         rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
@@ -1803,7 +1803,7 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *oldflp4,
         }
 }
 
-static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *oldflp4,
+static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
                            const struct fib_result *res,
                            struct fib_info *fi, u16 type, u32 itag)
 {
@@ -1813,7 +1813,7 @@ static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *oldflp4,
                 if (FIB_RES_GW(*res) &&
                     FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
                         rt->rt_gateway = FIB_RES_GW(*res);
-                rt_init_metrics(rt, oldflp4, fi);
+                rt_init_metrics(rt, fl4, fi);
 #ifdef CONFIG_IP_ROUTE_CLASSID
                 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
 #endif
@@ -2354,12 +2354,12 @@ EXPORT_SYMBOL(ip_route_input_common);
 /* called with rcu_read_lock() */
 static struct rtable *__mkroute_output(const struct fib_result *res,
                                        const struct flowi4 *fl4,
-                                       const struct flowi4 *oldflp4,
-                                       struct net_device *dev_out,
+                                       __be32 orig_daddr, __be32 orig_saddr,
+                                       int orig_oif, struct net_device *dev_out,
                                        unsigned int flags)
 {
         struct fib_info *fi = res->fi;
-        u32 tos = RT_FL_TOS(oldflp4);
+        u32 tos = RT_FL_TOS(fl4);
         struct in_device *in_dev;
         u16 type = res->type;
         struct rtable *rth;
@@ -2386,8 +2386,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
                 fi = NULL;
         } else if (type == RTN_MULTICAST) {
                 flags |= RTCF_MULTICAST | RTCF_LOCAL;
-                if (!ip_check_mc_rcu(in_dev, oldflp4->daddr, oldflp4->saddr,
-                                     oldflp4->flowi4_proto))
+                if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
+                                     fl4->flowi4_proto))
                         flags &= ~RTCF_LOCAL;
                 /* If multicast route do not exist use
                  * default one, but do not gateway in this case.
@@ -2405,8 +2405,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 
         rth->dst.output = ip_output;
 
-        rth->rt_key_dst = oldflp4->daddr;
-        rth->rt_key_src = oldflp4->saddr;
+        rth->rt_key_dst = orig_daddr;
+        rth->rt_key_src = orig_saddr;
         rth->rt_genid = rt_genid(dev_net(dev_out));
         rth->rt_flags   = flags;
         rth->rt_type    = type;
@@ -2414,9 +2414,9 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
         rth->rt_dst     = fl4->daddr;
         rth->rt_src     = fl4->saddr;
         rth->rt_route_iif = 0;
-        rth->rt_iif     = oldflp4->flowi4_oif ? : dev_out->ifindex;
-        rth->rt_oif     = oldflp4->flowi4_oif;
-        rth->rt_mark    = oldflp4->flowi4_mark;
+        rth->rt_iif     = orig_oif ? : dev_out->ifindex;
+        rth->rt_oif     = orig_oif;
+        rth->rt_mark    = fl4->flowi4_mark;
         rth->rt_gateway = fl4->daddr;
         rth->rt_spec_dst= fl4->saddr;
         rth->rt_peer_genid = 0;
@@ -2439,7 +2439,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 #ifdef CONFIG_IP_MROUTE
                 if (type == RTN_MULTICAST) {
                         if (IN_DEV_MFORWARD(in_dev) &&
-                            !ipv4_is_local_multicast(oldflp4->daddr)) {
+                            !ipv4_is_local_multicast(fl4->daddr)) {
                                 rth->dst.input = ip_mr_input;
                                 rth->dst.output = ip_mc_output;
                         }
@@ -2447,7 +2447,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 #endif
         }
 
-        rt_set_nexthop(rth, oldflp4, res, fi, type, 0);
+        rt_set_nexthop(rth, fl4, res, fi, type, 0);
 
         return rth;
 }
@@ -2457,36 +2457,37 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
  * called with rcu_read_lock();
  */
 
-static struct rtable *ip_route_output_slow(struct net *net,
-                                           const struct flowi4 *oldflp4)
+static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
 {
-        u32 tos = RT_FL_TOS(oldflp4);
-        struct flowi4 fl4;
-        struct fib_result res;
-        unsigned int flags = 0;
         struct net_device *dev_out = NULL;
+        u32 tos = RT_FL_TOS(fl4);
+        unsigned int flags = 0;
+        struct fib_result res;
         struct rtable *rth;
+        __be32 orig_daddr;
+        __be32 orig_saddr;
+        int orig_oif;
 
         res.fi          = NULL;
 #ifdef CONFIG_IP_MULTIPLE_TABLES
         res.r           = NULL;
 #endif
 
-        fl4.flowi4_oif = oldflp4->flowi4_oif;
-        fl4.flowi4_iif = net->loopback_dev->ifindex;
-        fl4.flowi4_mark = oldflp4->flowi4_mark;
-        fl4.daddr = oldflp4->daddr;
-        fl4.saddr = oldflp4->saddr;
-        fl4.flowi4_tos = tos & IPTOS_RT_MASK;
-        fl4.flowi4_scope = ((tos & RTO_ONLINK) ?
-                        RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
+        orig_daddr = fl4->daddr;
+        orig_saddr = fl4->saddr;
+        orig_oif = fl4->flowi4_oif;
+
+        fl4->flowi4_iif = net->loopback_dev->ifindex;
+        fl4->flowi4_tos = tos & IPTOS_RT_MASK;
+        fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
+                         RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
 
         rcu_read_lock();
-        if (oldflp4->saddr) {
+        if (fl4->saddr) {
                 rth = ERR_PTR(-EINVAL);
-                if (ipv4_is_multicast(oldflp4->saddr) ||
-                    ipv4_is_lbcast(oldflp4->saddr) ||
-                    ipv4_is_zeronet(oldflp4->saddr))
+                if (ipv4_is_multicast(fl4->saddr) ||
+                    ipv4_is_lbcast(fl4->saddr) ||
+                    ipv4_is_zeronet(fl4->saddr))
                         goto out;
 
                 /* I removed check for oif == dev_out->oif here.
@@ -2497,11 +2498,11 @@ static struct rtable *ip_route_output_slow(struct net *net,
                       of another iface. --ANK
                  */
 
-                if (oldflp4->flowi4_oif == 0 &&
-                    (ipv4_is_multicast(oldflp4->daddr) ||
-                     ipv4_is_lbcast(oldflp4->daddr))) {
+                if (fl4->flowi4_oif == 0 &&
+                    (ipv4_is_multicast(fl4->daddr) ||
+                     ipv4_is_lbcast(fl4->daddr))) {
                         /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
-                        dev_out = __ip_dev_find(net, oldflp4->saddr, false);
+                        dev_out = __ip_dev_find(net, fl4->saddr, false);
                         if (dev_out == NULL)
                                 goto out;
 
@@ -2520,20 +2521,20 @@ static struct rtable *ip_route_output_slow(struct net *net,
                            Luckily, this hack is good workaround.
                          */
 
-                        fl4.flowi4_oif = dev_out->ifindex;
+                        fl4->flowi4_oif = dev_out->ifindex;
                         goto make_route;
                 }
 
-                if (!(oldflp4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
+                if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
                         /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
-                        if (!__ip_dev_find(net, oldflp4->saddr, false))
+                        if (!__ip_dev_find(net, fl4->saddr, false))
                                 goto out;
                 }
         }
 
 
-        if (oldflp4->flowi4_oif) {
-                dev_out = dev_get_by_index_rcu(net, oldflp4->flowi4_oif);
+        if (fl4->flowi4_oif) {
+                dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
                 rth = ERR_PTR(-ENODEV);
                 if (dev_out == NULL)
                         goto out;
@@ -2543,37 +2544,37 @@ static struct rtable *ip_route_output_slow(struct net *net,
                         rth = ERR_PTR(-ENETUNREACH);
                         goto out;
                 }
-                if (ipv4_is_local_multicast(oldflp4->daddr) ||
-                    ipv4_is_lbcast(oldflp4->daddr)) {
-                        if (!fl4.saddr)
-                                fl4.saddr = inet_select_addr(dev_out, 0,
-                                                             RT_SCOPE_LINK);
+                if (ipv4_is_local_multicast(fl4->daddr) ||
+                    ipv4_is_lbcast(fl4->daddr)) {
+                        if (!fl4->saddr)
+                                fl4->saddr = inet_select_addr(dev_out, 0,
+                                                              RT_SCOPE_LINK);
                         goto make_route;
                 }
-                if (!fl4.saddr) {
-                        if (ipv4_is_multicast(oldflp4->daddr))
-                                fl4.saddr = inet_select_addr(dev_out, 0,
-                                                             fl4.flowi4_scope);
-                        else if (!oldflp4->daddr)
-                                fl4.saddr = inet_select_addr(dev_out, 0,
-                                                             RT_SCOPE_HOST);
+                if (fl4->saddr) {
+                        if (ipv4_is_multicast(fl4->daddr))
+                                fl4->saddr = inet_select_addr(dev_out, 0,
+                                                              fl4->flowi4_scope);
+                        else if (!fl4->daddr)
+                                fl4->saddr = inet_select_addr(dev_out, 0,
+                                                              RT_SCOPE_HOST);
                 }
         }
 
-        if (!fl4.daddr) {
-                fl4.daddr = fl4.saddr;
-                if (!fl4.daddr)
-                        fl4.daddr = fl4.saddr = htonl(INADDR_LOOPBACK);
+        if (!fl4->daddr) {
+                fl4->daddr = fl4->saddr;
+                if (!fl4->daddr)
+                        fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
                 dev_out = net->loopback_dev;
-                fl4.flowi4_oif = net->loopback_dev->ifindex;
+                fl4->flowi4_oif = net->loopback_dev->ifindex;
                 res.type = RTN_LOCAL;
                 flags |= RTCF_LOCAL;
                 goto make_route;
         }
 
-        if (fib_lookup(net, &fl4, &res)) {
+        if (fib_lookup(net, fl4, &res)) {
                 res.fi = NULL;
-                if (oldflp4->flowi4_oif) {
+                if (fl4->flowi4_oif) {
                         /* Apparently, routing tables are wrong. Assume,
                            that the destination is on link.
 
@@ -2592,9 +2593,9 @@ static struct rtable *ip_route_output_slow(struct net *net,
                            likely IPv6, but we do not.
                          */
 
-                        if (fl4.saddr == 0)
-                                fl4.saddr = inet_select_addr(dev_out, 0,
-                                                             RT_SCOPE_LINK);
+                        if (fl4->saddr == 0)
+                                fl4->saddr = inet_select_addr(dev_out, 0,
+                                                              RT_SCOPE_LINK);
                         res.type = RTN_UNICAST;
                         goto make_route;
                 }
@@ -2603,44 +2604,45 @@ static struct rtable *ip_route_output_slow(struct net *net,
         }
 
         if (res.type == RTN_LOCAL) {
-                if (!fl4.saddr) {
+                if (!fl4->saddr) {
                         if (res.fi->fib_prefsrc)
-                                fl4.saddr = res.fi->fib_prefsrc;
+                                fl4->saddr = res.fi->fib_prefsrc;
                         else
-                                fl4.saddr = fl4.daddr;
+                                fl4->saddr = fl4->daddr;
                 }
                 dev_out = net->loopback_dev;
-                fl4.flowi4_oif = dev_out->ifindex;
+                fl4->flowi4_oif = dev_out->ifindex;
                 res.fi = NULL;
                 flags |= RTCF_LOCAL;
                 goto make_route;
         }
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-        if (res.fi->fib_nhs > 1 && fl4.flowi4_oif == 0)
+        if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
                 fib_select_multipath(&res);
         else
 #endif
         if (!res.prefixlen &&
             res.table->tb_num_default > 1 &&
-            res.type == RTN_UNICAST && !fl4.flowi4_oif)
+            res.type == RTN_UNICAST && !fl4->flowi4_oif)
                 fib_select_default(&res);
 
-        if (!fl4.saddr)
-                fl4.saddr = FIB_RES_PREFSRC(net, res);
+        if (!fl4->saddr)
+                fl4->saddr = FIB_RES_PREFSRC(net, res);
 
         dev_out = FIB_RES_DEV(res);
-        fl4.flowi4_oif = dev_out->ifindex;
+        fl4->flowi4_oif = dev_out->ifindex;
 
 
 make_route:
-        rth = __mkroute_output(&res, &fl4, oldflp4, dev_out, flags);
+        rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
+                               dev_out, flags);
         if (!IS_ERR(rth)) {
                 unsigned int hash;
 
-                hash = rt_hash(oldflp4->daddr, oldflp4->saddr, oldflp4->flowi4_oif,
+                hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
                                rt_genid(dev_net(dev_out)));
-                rth = rt_intern_hash(hash, rth, NULL, oldflp4->flowi4_oif);
+                rth = rt_intern_hash(hash, rth, NULL, orig_oif);
         }
 
 out:
@@ -2648,7 +2650,7 @@ out:
         return rth;
 }
 
-struct rtable *__ip_route_output_key(struct net *net, const struct flowi4 *flp4)
+struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
 {
         struct rtable *rth;
         unsigned int hash;