ipv4: Use const'ify fib_result deep in the route call chains.

The only troublesome bit here is __mkroute_output which wants
to override res->fi and res->type, compute those in local
variables instead.

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

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index b3019d89e8bedb01b3da8240390af59f3bdfc2af..523a170b0ecb3d9e45951947b3e3ab7e314ea666 100644 (file)
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -202,7 +202,7 @@ extern int __net_init fib4_rules_init(struct net *net);
 extern void __net_exit fib4_rules_exit(struct net *net);
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
-extern u32 fib_rules_tclass(struct fib_result *res);
+extern u32 fib_rules_tclass(const struct fib_result *res);
 #endif
 
 extern int fib_lookup(struct net *n, struct flowi *flp, struct fib_result *res);

diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index 9cefe72029cf04f473d5a80d03cce15a37cd19ec..3018efbaea77ec32f8d42236fe534f6c8a8dc336 100644 (file)
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -47,7 +47,7 @@ struct fib4_rule {
 };
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
-u32 fib_rules_tclass(struct fib_result *res)
+u32 fib_rules_tclass(const struct fib_result *res)
 {
        return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
 }

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 9841543c468dbd2d1e4f5de4a603930b75ac4e3a..2facde0985f9496e313be06854befebb2a80baa2 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1787,10 +1787,10 @@ static void rt_init_metrics(struct rtable *rt, struct fib_info *fi)
        }
 }
 
-static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
+static void rt_set_nexthop(struct rtable *rt, const struct fib_result *res,
+                          struct fib_info *fi, u16 type, u32 itag)
 {
        struct dst_entry *dst = &rt->dst;
-       struct fib_info *fi = res->fi;
 
        if (fi) {
                if (FIB_RES_GW(*res) &&
@@ -1813,7 +1813,7 @@ static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
 #endif
        set_class_tag(rt, itag);
 #endif
-       rt->rt_type = res->type;
+       rt->rt_type = type;
 }
 
 static struct rtable *rt_dst_alloc(bool nopolicy, bool noxfrm)
@@ -1939,7 +1939,7 @@ static void ip_handle_martian_source(struct net_device *dev,
 
 /* called in rcu_read_lock() section */
 static int __mkroute_input(struct sk_buff *skb,
-                          struct fib_result *res,
+                          const struct fib_result *res,
                           struct in_device *in_dev,
                           __be32 daddr, __be32 saddr, u32 tos,
                           struct rtable **result)
@@ -2018,7 +2018,7 @@ static int __mkroute_input(struct sk_buff *skb,
        rth->dst.output = ip_output;
        rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
 
-       rt_set_nexthop(rth, res, itag);
+       rt_set_nexthop(rth, res, res->fi, res->type, itag);
 
        rth->rt_flags = flags;
 
@@ -2319,23 +2319,25 @@ skip_cache:
 EXPORT_SYMBOL(ip_route_input_common);
 
 /* called with rcu_read_lock() */
-static struct rtable *__mkroute_output(struct fib_result *res,
+static struct rtable *__mkroute_output(const struct fib_result *res,
                                       const struct flowi *fl,
                                       const struct flowi *oldflp,
                                       struct net_device *dev_out,
                                       unsigned int flags)
 {
+       struct fib_info *fi = res->fi;
        u32 tos = RT_FL_TOS(oldflp);
        struct in_device *in_dev;
+       u16 type = res->type;
        struct rtable *rth;
 
        if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
                return ERR_PTR(-EINVAL);
 
        if (ipv4_is_lbcast(fl->fl4_dst))
-               res->type = RTN_BROADCAST;
+               type = RTN_BROADCAST;
        else if (ipv4_is_multicast(fl->fl4_dst))
-               res->type = RTN_MULTICAST;
+               type = RTN_MULTICAST;
        else if (ipv4_is_zeronet(fl->fl4_dst))
                return ERR_PTR(-EINVAL);
 
@@ -2346,10 +2348,10 @@ static struct rtable *__mkroute_output(struct fib_result *res,
        if (!in_dev)
                return ERR_PTR(-EINVAL);
 
-       if (res->type == RTN_BROADCAST) {
+       if (type == RTN_BROADCAST) {
                flags |= RTCF_BROADCAST | RTCF_LOCAL;
-               res->fi = NULL;
-       } else if (res->type == RTN_MULTICAST) {
+               fi = NULL;
+       } else if (type == RTN_MULTICAST) {
                flags |= RTCF_MULTICAST | RTCF_LOCAL;
                if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
                                 oldflp->proto))
@@ -2358,8 +2360,8 @@ static struct rtable *__mkroute_output(struct fib_result *res,
                 * default one, but do not gateway in this case.
                 * Yes, it is hack.
                 */
-               if (res->fi && res->prefixlen < 4)
-                       res->fi = NULL;
+               if (fi && res->prefixlen < 4)
+                       fi = NULL;
        }
 
        rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
@@ -2399,7 +2401,7 @@ static struct rtable *__mkroute_output(struct fib_result *res,
                        RT_CACHE_STAT_INC(out_slow_mc);
                }
 #ifdef CONFIG_IP_MROUTE
-               if (res->type == RTN_MULTICAST) {
+               if (type == RTN_MULTICAST) {
                        if (IN_DEV_MFORWARD(in_dev) &&
                            !ipv4_is_local_multicast(oldflp->fl4_dst)) {
                                rth->dst.input = ip_mr_input;
@@ -2409,7 +2411,7 @@ static struct rtable *__mkroute_output(struct fib_result *res,
 #endif
        }
 
-       rt_set_nexthop(rth, res, 0);
+       rt_set_nexthop(rth, res, fi, type, 0);
 
        rth->rt_flags = flags;
        return rth;