[NETLINK]: Do precise netlink message allocations where possible

Account for the netlink message header size directly in nlmsg_new()
instead of relying on the caller calculate it correctly.

Replaces error handling of message construction functions when
constructing notifications with bug traps since a failure implies
a bug in calculating the size of the skb.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Graf 2006-11-10 14:10:15 -08:00 committed by David S. Miller
parent a94f723d59
commit 339bf98ffc
21 changed files with 233 additions and 107 deletions

View file

@ -273,25 +273,49 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev)
return -1;
}
static inline size_t fib_nlmsg_size(struct fib_info *fi)
{
size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
+ nla_total_size(4) /* RTA_TABLE */
+ nla_total_size(4) /* RTA_DST */
+ nla_total_size(4) /* RTA_PRIORITY */
+ nla_total_size(4); /* RTA_PREFSRC */
/* 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 flow and gateway attribute */
nhsize += 2 * nla_total_size(4);
/* all nexthops are packed in a nested attribute */
payload += nla_total_size(fi->fib_nhs * nhsize);
}
return payload;
}
void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
int dst_len, u32 tb_id, struct nl_info *info)
{
struct sk_buff *skb;
int payload = sizeof(struct rtmsg) + 256;
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
int err = -ENOBUFS;
skb = nlmsg_new(nlmsg_total_size(payload), GFP_KERNEL);
skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
if (skb == NULL)
goto errout;
err = fib_dump_info(skb, info->pid, seq, event, tb_id,
fa->fa_type, fa->fa_scope, key, dst_len,
fa->fa_tos, fa->fa_info, 0);
if (err < 0) {
kfree_skb(skb);
goto errout;
}
/* failure implies BUG in fib_nlmsg_size() */
BUG_ON(err < 0);
err = rtnl_notify(skb, info->pid, RTNLGRP_IPV4_ROUTE,
info->nlh, GFP_KERNEL);