From patchwork Mon Mar 26 22:05:02 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Leblond X-Patchwork-Id: 148841 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 26E21B6EEA for ; Tue, 27 Mar 2012 09:46:11 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756978Ab2CZWqJ (ORCPT ); Mon, 26 Mar 2012 18:46:09 -0400 Received: from ks28632.kimsufi.com ([91.121.96.152]:45397 "EHLO ks28632.kimsufi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752302Ab2CZWqI (ORCPT ); Mon, 26 Mar 2012 18:46:08 -0400 X-Greylist: delayed 2397 seconds by postgrey-1.27 at vger.kernel.org; Mon, 26 Mar 2012 18:46:07 EDT Received: from ip-92-50-100-48.unitymediagroup.de ([92.50.100.48] helo=tiger.regit.org) by ks28632.kimsufi.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1SCI3I-00066X-TQ; Tue, 27 Mar 2012 00:06:13 +0200 From: Eric Leblond To: pablo@netfilter.org Cc: netfilter-devel@vger.kernel.org, Eric Leblond Subject: [PATCH] conntrack: add /proc entry to disable helper by default Date: Tue, 27 Mar 2012 00:05:02 +0200 Message-Id: <1332799502-11623-2-git-send-email-eric@regit.org> X-Mailer: git-send-email 1.7.9.1 In-Reply-To: <1332799502-11623-1-git-send-email-eric@regit.org> References: <1332799502-11623-1-git-send-email-eric@regit.org> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org This patch give the user different methods to disable the attachment of helper to all connections on a given port. The idea is to allow the user to choose with the CT target the helper assignement he wants to have. First method it to use the 'no_helper_assign' option on the nf_conntrack module. As this is a constraint to do this at the time of the loading, a /proc entry is also available. Setting sys/net/netfilter/nf_conntrack_no_helper_assign to 1 will disable the automatic assignement of the helper. The user will --- include/net/netfilter/nf_conntrack_helper.h | 3 + include/net/netns/conntrack.h | 2 + net/netfilter/nf_conntrack_core.c | 6 ++ net/netfilter/nf_conntrack_helper.c | 79 ++++++++++++++++++++++++++- 4 files changed, 88 insertions(+), 2 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h index f1c1311..abd2fc83 100644 --- a/include/net/netfilter/nf_conntrack_helper.h +++ b/include/net/netfilter/nf_conntrack_helper.h @@ -63,6 +63,9 @@ static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct) extern int nf_conntrack_helper_init(void); extern void nf_conntrack_helper_fini(void); +extern int nf_conntrack_helper_init_net(struct net *net); +extern void nf_conntrack_helper_fini_net(struct net *net); + extern int nf_conntrack_broadcast_help(struct sk_buff *skb, unsigned int protoff, struct nf_conn *ct, diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h index 7a911ec..2395288 100644 --- a/include/net/netns/conntrack.h +++ b/include/net/netns/conntrack.h @@ -26,11 +26,13 @@ struct netns_ct { int sysctl_tstamp; int sysctl_checksum; unsigned int sysctl_log_invalid; /* Log invalid packets */ + int sysctl_no_helper_assign; #ifdef CONFIG_SYSCTL struct ctl_table_header *sysctl_header; struct ctl_table_header *acct_sysctl_header; struct ctl_table_header *tstamp_sysctl_header; struct ctl_table_header *event_sysctl_header; + struct ctl_table_header *helper_sysctl_header; #endif char *slabname; }; diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 76613f5..5faeb75 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1301,6 +1301,7 @@ static void nf_conntrack_cleanup_net(struct net *net) nf_conntrack_tstamp_fini(net); nf_conntrack_acct_fini(net); nf_conntrack_expect_fini(net); + nf_conntrack_helper_fini_net(net); kmem_cache_destroy(net->ct.nf_conntrack_cachep); kfree(net->ct.slabname); free_percpu(net->ct.stat); @@ -1528,9 +1529,14 @@ static int nf_conntrack_init_net(struct net *net) ret = nf_conntrack_ecache_init(net); if (ret < 0) goto err_ecache; + ret = nf_conntrack_helper_init_net(net); + if (ret < 0) + goto err_helper; return 0; +err_helper: + nf_conntrack_helper_fini_net(net); err_ecache: nf_conntrack_tstamp_fini(net); err_tstamp: diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index bbe23ba..9663494 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -34,6 +34,67 @@ static struct hlist_head *nf_ct_helper_hash __read_mostly; static unsigned int nf_ct_helper_hsize __read_mostly; static unsigned int nf_ct_helper_count __read_mostly; +static bool nf_ct_no_helper_assign __read_mostly; +module_param_named(no_helper_assign, nf_ct_no_helper_assign, bool, 0644); +MODULE_PARM_DESC(no_helper_assign, "Do not assign helper to connection based on port."); + +#ifdef CONFIG_SYSCTL +static struct ctl_table helper_sysctl_table[] = { + { + .procname = "nf_conntrack_no_helper_assign", + .data = &init_net.ct.sysctl_no_helper_assign, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + {} +}; + +static int nf_conntrack_helper_init_sysctl(struct net *net) +{ + struct ctl_table *table; + + table = kmemdup(helper_sysctl_table, sizeof(helper_sysctl_table), + GFP_KERNEL); + if (!table) + goto out; + + table[0].data = &net->ct.sysctl_no_helper_assign; + + net->ct.helper_sysctl_header = register_net_sysctl_table(net, + nf_net_netfilter_sysctl_path, table); + if (!net->ct.helper_sysctl_header) { + printk(KERN_ERR "nf_conntrack_helper: can't register to sysctl.\n"); + goto out_register; + } + return 0; + +out_register: + kfree(table); +out: + return -ENOMEM; +} + +static void nf_conntrack_helper_fini_sysctl(struct net *net) +{ + struct ctl_table *table; + + table = net->ct.helper_sysctl_header->ctl_table_arg; + unregister_net_sysctl_table(net->ct.helper_sysctl_header); + kfree(table); +} +#else +static int nf_conntrack_helper_init_sysctl(struct net *net) +{ + return 0; +} + +static void nf_conntrack_helper_fini_sysctl(struct net *net) +{ +} +#endif /* CONFIG_SYSCTL */ + + /* Stupid hash, but collision free for the default registrations of the * helpers currently in the kernel. */ @@ -118,6 +179,7 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, { struct nf_conntrack_helper *helper = NULL; struct nf_conn_help *help; + struct net *net = nf_ct_net(ct); int ret = 0; if (tmpl != NULL) { @@ -127,8 +189,10 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, } help = nfct_help(ct); - if (helper == NULL) + + if ((helper == NULL) && !net->ct.sysctl_no_helper_assign) helper = __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); + if (helper == NULL) { if (help) RCU_INIT_POINTER(help->helper, NULL); @@ -273,7 +337,6 @@ int nf_conntrack_helper_init(void) err = nf_ct_extend_register(&helper_extend); if (err < 0) goto err1; - return 0; err1: @@ -281,8 +344,20 @@ err1: return err; } +int nf_conntrack_helper_init_net(struct net *net) +{ + net->ct.sysctl_no_helper_assign = nf_ct_no_helper_assign; + + return nf_conntrack_helper_init_sysctl(net); +} + void nf_conntrack_helper_fini(void) { nf_ct_extend_unregister(&helper_extend); nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize); } + +void nf_conntrack_helper_fini_net(struct net *net) +{ + nf_conntrack_helper_fini_sysctl(net); +}