[NETLINK]: Do precise netlink message allocations where possible

[net-next-2.6.git] / net / decnet / dn_table.c

diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
index 317904bb589645c422cce41d9d653dc0227f4899..e74b744254ab0ebb7041155d0daf051c5b66c2c4 100644 (file)
--- a/net/decnet/dn_table.c
+++ b/net/decnet/dn_table.c
@@ -263,6 +263,32 @@ static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern
        return 0;
 }
 
+static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
+{
+       size_t payload = NLMSG_ALIGN(struct rtmsg)
+                        + nla_total_size(4) /* RTA_TABLE */
+                        + nla_total_size(2) /* RTA_DST */
+                        + nla_total_size(4); /* RTA_PRIORITY */
+
+       /* space for nested metrics */
+       payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
+
+       if (fi->fib_nhs) {
+               /* Also handles the special case fib_nhs == 1 */
+
+               /* each nexthop is packed in an attribute */
+               size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
+
+               /* may contain a gateway attribute */
+               nhsize += nla_total_size(4);
+
+               /* all nexthops are packed in a nested attribute */
+               payload += nla_total_size(fi->fib_nhs * nhsize);
+       }
+
+       return payload;
+}
+
 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
                         struct dn_fib_info *fi, unsigned int flags)
@@ -335,17 +361,15 @@ static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
         u32 pid = req ? req->pid : 0;
        int err = -ENOBUFS;
 
-        skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f), GFP_KERNEL));
         if (skb == NULL)
                goto errout;
 
         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
                               f->fn_type, f->fn_scope, &f->fn_key, z,
                               DN_FIB_INFO(f), 0);
-       if (err < 0) {
-                kfree_skb(skb);
-               goto errout;
-        }
+       /* failure implies BUG in dn_fib_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 errout: