From bc01befdcf3e40979eb518085a075cbf0aacede0 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 28 Sep 2010 21:06:34 +0200 Subject: netfilter: ctnetlink: add support for user-space expectation helpers This patch adds the basic infrastructure to support user-space expectation helpers via ctnetlink and the netfilter queuing infrastructure NFQUEUE. Basically, this patch: * adds NF_CT_EXPECT_USERSPACE flag to identify user-space created expectations. I have also added a sanity check in __nf_ct_expect_check() to avoid that kernel-space helpers may create an expectation if the master conntrack has no helper assigned. * adds some branches to check if the master conntrack helper exists, otherwise we skip the code that refers to kernel-space helper such as the local expectation list and the expectation policy. * allows to set the timeout for user-space expectations with no helper assigned. * a list of expectations created from user-space that depends on ctnetlink (if this module is removed, they are deleted). * includes USERSPACE in the /proc output for expectations that have been created by a user-space helper. This patch also modifies ctnetlink to skip including the helper name in the Netlink messages if no kernel-space helper is set (since no user-space expectation has not kernel-space kernel assigned). You can access an example user-space FTP conntrack helper at: http://people.netfilter.org/pablo/userspace-conntrack-helpers/nf-ftp-helper-userspace-POC.tar.bz Signed-off-by: Pablo Neira Ayuso Signed-off-by: Patrick McHardy --- include/linux/netfilter/nf_conntrack_common.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/netfilter/nf_conntrack_common.h') diff --git a/include/linux/netfilter/nf_conntrack_common.h b/include/linux/netfilter/nf_conntrack_common.h index fdc50cae861f..23a1a08578a8 100644 --- a/include/linux/netfilter/nf_conntrack_common.h +++ b/include/linux/netfilter/nf_conntrack_common.h @@ -103,6 +103,7 @@ enum ip_conntrack_expect_events { /* expectation flags */ #define NF_CT_EXPECT_PERMANENT 0x1 #define NF_CT_EXPECT_INACTIVE 0x2 +#define NF_CT_EXPECT_USERSPACE 0x4 #ifdef __KERNEL__ struct ip_conntrack_stat { -- cgit