netfilter: nfnetlink: cleanup for nfnetlink_rcv_msg() function

This patch cleans up the message handling path in two aspects:

 * it uses NLMSG_LENGTH() instead of NLMSG_SPACE() like rtnetlink
does in this case to check if there is enough room for the
Netlink/nfnetlink headers. No need to check for the padding room.

 * it removes a redundant header size checking that has been
 already do at the beginning of the function.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2009-06-02 20:03:33 +02:00 committed by pablo
parent 874ab9233e
commit f49c857ff2

View File

@ -136,7 +136,7 @@ static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
return -EPERM;
/* All the messages must at least contain nfgenmsg */
if (nlh->nlmsg_len < NLMSG_SPACE(sizeof(struct nfgenmsg)))
if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct nfgenmsg)))
return 0;
type = nlh->nlmsg_type;
@ -160,19 +160,14 @@ replay:
{
int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
u_int16_t attr_count = ss->cb[cb_id].attr_count;
struct nlattr *cda[attr_count+1];
struct nlattr *cda[ss->cb[cb_id].attr_count + 1];
struct nlattr *attr = (void *)nlh + min_len;
int attrlen = nlh->nlmsg_len - min_len;
if (likely(nlh->nlmsg_len >= min_len)) {
struct nlattr *attr = (void *)nlh + NLMSG_ALIGN(min_len);
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
err = nla_parse(cda, attr_count, attr, attrlen,
ss->cb[cb_id].policy);
if (err < 0)
return err;
} else
return -EINVAL;
err = nla_parse(cda, ss->cb[cb_id].attr_count,
attr, attrlen, ss->cb[cb_id].policy);
if (err < 0)
return err;
err = nc->call(nfnl, skb, nlh, cda);
if (err == -EAGAIN)