[PATCH] [IPV6] use offsetof().

[YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@xxxxxxxxxxxxxx>]

Hello.

D: use offsetof().

Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx>

===== net/ipv6/ip6_fib.c 1.26 vs edited =====
--- 1.26/net/ipv6/ip6_fib.c     2004-07-30 07:30:01 +09:00
+++ edited/net/ipv6/ip6_fib.c   2004-08-21 01:19:44 +09:00
@@ -514,7 +514,7 @@
        int err = -ENOMEM;
 
        fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
-                       rt->rt6i_dst.plen, (u8*) &rt->rt6i_dst - (u8*) rt);
+                       rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
 
        if (fn == NULL)
                goto out;
@@ -550,7 +550,7 @@
 
                        sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
                                        sizeof(struct in6_addr), 
rt->rt6i_src.plen,
-                                       (u8*) &rt->rt6i_src - (u8*) rt);
+                                       offsetof(struct rt6_info, rt6i_src));
 
                        if (sn == NULL) {
                                /* If it is failed, discard just allocated
@@ -571,7 +571,7 @@
                } else {
                        sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
                                        sizeof(struct in6_addr), 
rt->rt6i_src.plen,
-                                       (u8*) &rt->rt6i_src - (u8*) rt);
+                                       offsetof(struct rt6_info, rt6i_src));
 
                        if (sn == NULL)
                                goto st_failure;
@@ -680,14 +680,13 @@
                               struct in6_addr *saddr)
 {
        struct lookup_args args[2];
-       struct rt6_info *rt = NULL;
        struct fib6_node *fn;
 
-       args[0].offset = (u8*) &rt->rt6i_dst - (u8*) rt;
+       args[0].offset = offsetof(struct rt6_info, rt6i_dst);
        args[0].addr = daddr;
 
 #ifdef CONFIG_IPV6_SUBTREES
-       args[1].offset = (u8*) &rt->rt6i_src - (u8*) rt;
+       args[1].offset = offsetof(struct rt6_info, rt6i_src);
        args[1].addr = saddr;
 #endif
 
@@ -739,11 +738,10 @@
                               struct in6_addr *daddr, int dst_len,
                               struct in6_addr *saddr, int src_len)
 {
-       struct rt6_info *rt = NULL;
        struct fib6_node *fn;
 
        fn = fib6_locate_1(root, daddr, dst_len,
-                          (u8*) &rt->rt6i_dst - (u8*) rt);
+                          offsetof(struct rt6_info, rt6i_dst));
 
 #ifdef CONFIG_IPV6_SUBTREES
        if (src_len) {
@@ -752,7 +750,7 @@
                        fn = fn->subtree;
                if (fn)
                        fn = fib6_locate_1(fn, saddr, src_len,
-                                          (u8*) &rt->rt6i_src - (u8*) rt);
+                                          offsetof(struct rt6_info, rt6i_src));
        }
 #endif