From 339231537506846cb232a2f0cc4a2c662b2d5b07 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 10 Oct 2005 21:23:28 -0700
Subject: [PATCH] [NETFILTER] ctnetlink: allow userspace to change TCP state
This patch adds the ability of changing the state a TCP connection. I know
that this must be used with care but it's required to provide a complete
conntrack creation via conntrack_netlink. So I'll document this aspect on
the upcoming docs.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
.../netfilter_ipv4/ip_conntrack_protocol.h | 3 +++
net/ipv4/netfilter/ip_conntrack_proto_tcp.c | 23 +++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/include/linux/netfilter_ipv4/ip_conntrack_protocol.h b/include/linux/netfilter_ipv4/ip_conntrack_protocol.h
index b6b99be8632..2c76b879e3d 100644
--- a/include/linux/netfilter_ipv4/ip_conntrack_protocol.h
+++ b/include/linux/netfilter_ipv4/ip_conntrack_protocol.h
@@ -52,6 +52,9 @@ struct ip_conntrack_protocol
int (*to_nfattr)(struct sk_buff *skb, struct nfattr *nfa,
const struct ip_conntrack *ct);
+ /* convert nfnetlink attributes to protoinfo */
+ int (*from_nfattr)(struct nfattr *tb[], struct ip_conntrack *ct);
+
int (*tuple_to_nfattr)(struct sk_buff *skb,
const struct ip_conntrack_tuple *t);
int (*nfattr_to_tuple)(struct nfattr *tb[],
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 75e27e65c28..d6701cafbcc 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -356,6 +356,28 @@ nfattr_failure:
read_unlock_bh(&tcp_lock);
return -1;
}
+
+static int nfattr_to_tcp(struct nfattr *cda[], struct ip_conntrack *ct)
+{
+ struct nfattr *attr = cda[CTA_PROTOINFO_TCP-1];
+ struct nfattr *tb[CTA_PROTOINFO_TCP_MAX];
+
+ if (nfattr_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, attr) < 0)
+ goto nfattr_failure;
+
+ if (!tb[CTA_PROTOINFO_TCP_STATE-1])
+ return -EINVAL;
+
+ write_lock_bh(&tcp_lock);
+ ct->proto.tcp.state =
+ *(u_int8_t *)NFA_DATA(tb[CTA_PROTOINFO_TCP_STATE-1]);
+ write_unlock_bh(&tcp_lock);
+
+ return 0;
+
+nfattr_failure:
+ return -1;
+}
#endif
static unsigned int get_conntrack_index(const struct tcphdr *tcph)
@@ -1127,6 +1149,7 @@ struct ip_conntrack_protocol ip_conntrack_protocol_tcp =
#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
.to_nfattr = tcp_to_nfattr,
+ .from_nfattr = nfattr_to_tcp,
.tuple_to_nfattr = ip_ct_port_tuple_to_nfattr,
.nfattr_to_tuple = ip_ct_port_nfattr_to_tuple,
#endif
--
2.41.3