commit ae243bee397102c51fbf9db440eca3b077e0e702
author Pablo Neira Ayuso <pablo@netfilter.org> Thu Jun 07 14:19:42 2012 +0200
committer Pablo Neira Ayuso <pablo@netfilter.org> Sat Jun 16 15:09:15 2012 +0200
tree e2320f565fe03c500ed3356b82cc6fbed0a6fe81
parent 8c88f87cb27ad09086940bdd3e6955e5325ec89a

netfilter: ctnetlink: add CTA_HELP_INFO attribute

This attribute can be used to modify and to dump the internal
protocol information.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_netlink.c

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 8be0ab9..ae156df 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -902,7 +902,8 @@
 };
 
 static inline int
-ctnetlink_parse_help(const struct nlattr *attr, char **helper_name)
+ctnetlink_parse_help(const struct nlattr *attr, char **helper_name,
+		     struct nlattr **helpinfo)
 {
 	struct nlattr *tb[CTA_HELP_MAX+1];
 
@@ -913,6 +914,9 @@
 
 	*helper_name = nla_data(tb[CTA_HELP_NAME]);
 
+	if (tb[CTA_HELP_INFO])
+		*helpinfo = tb[CTA_HELP_INFO];
+
 	return 0;
 }
 
@@ -1173,13 +1177,14 @@
 	struct nf_conntrack_helper *helper;
 	struct nf_conn_help *help = nfct_help(ct);
 	char *helpname = NULL;
+	struct nlattr *helpinfo = NULL;
 	int err;
 
 	/* don't change helper of sibling connections */
 	if (ct->master)
 		return -EBUSY;
 
-	err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);
+	err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
 	if (err < 0)
 		return err;
 
@@ -1214,8 +1219,12 @@
 	}
 
 	if (help) {
-		if (help->helper == helper)
+		if (help->helper == helper) {
+			/* update private helper data if allowed. */
+			if (helper->from_nlattr && helpinfo)
+				helper->from_nlattr(helpinfo, ct);
 			return 0;
+		}
 		if (help->helper)
 			return -EBUSY;
 		/* need to zero data of old helper */
@@ -1411,8 +1420,9 @@
 	rcu_read_lock();
  	if (cda[CTA_HELP]) {
 		char *helpname = NULL;
- 
- 		err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);
+		struct nlattr *helpinfo = NULL;
+
+		err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
  		if (err < 0)
 			goto err2;
 
@@ -1446,6 +1456,9 @@
 				err = -ENOMEM;
 				goto err2;
 			}
+			/* set private helper data if allowed. */
+			if (helper->from_nlattr && helpinfo)
+				helper->from_nlattr(helpinfo, ct);
 
 			/* not in hash table yet so not strictly necessary */
 			RCU_INIT_POINTER(help->helper, helper);