Commit f49c857f authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso Committed by pablo
Browse files

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: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 874ab923

net/netfilter/nfnetlink.c

+9 −14
Original line number Diff line number Diff line
@@ -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);

		err = nla_parse(cda, ss->cb[cb_id].attr_count,

				attr, attrlen, ss->cb[cb_id].policy);

		if (err < 0)

			return err;

		} else

			return -EINVAL;



		err = nc->call(nfnl, skb, nlh, cda);

		if (err == -EAGAIN)

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