[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

@ -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: