--- /dev/null
+/* iptables module to match on related connections */
+/*
+ * (C) 2001 Martin Josefsson <gandalf@wlug.westbo.se>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 19 Mar 2002 Harald Welte <laforge@gnumonks.org>:
+ * - Port to newnat infrastructure
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter.h>
+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_conntrack_core.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#else
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#endif
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_helper.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Josefsson <gandalf@netfilter.org>");
+MODULE_DESCRIPTION("iptables helper match module");
+MODULE_ALIAS("ipt_helper");
+MODULE_ALIAS("ip6t_helper");
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct xt_match *match,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ const struct xt_helper_info *info = matchinfo;
+ struct ip_conntrack *ct;
+ enum ip_conntrack_info ctinfo;
+ int ret = info->invert;
+
+ ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
+ if (!ct) {
+ DEBUGP("xt_helper: Eek! invalid conntrack?\n");
+ return ret;
+ }
+
+ if (!ct->master) {
+ DEBUGP("xt_helper: conntrack %p has no master\n", ct);
+ return ret;
+ }
+
+ read_lock_bh(&ip_conntrack_lock);
+ if (!ct->master->helper) {
+ DEBUGP("xt_helper: master ct %p has no helper\n",
+ exp->expectant);
+ goto out_unlock;
+ }
+
+ DEBUGP("master's name = %s , info->name = %s\n",
+ ct->master->helper->name, info->name);
+
+ if (info->name[0] == '\0')
+ ret ^= 1;
+ else
+ ret ^= !strncmp(ct->master->helper->name, info->name,
+ strlen(ct->master->helper->name));
+out_unlock:
+ read_unlock_bh(&ip_conntrack_lock);
+ return ret;
+}
+
+#else /* CONFIG_IP_NF_CONNTRACK */
+
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct xt_match *match,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ const struct xt_helper_info *info = matchinfo;
+ struct nf_conn *ct;
+ struct nf_conn_help *master_help;
+ enum ip_conntrack_info ctinfo;
+ int ret = info->invert;
+
+ ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
+ if (!ct) {
+ DEBUGP("xt_helper: Eek! invalid conntrack?\n");
+ return ret;
+ }
+
+ if (!ct->master) {
+ DEBUGP("xt_helper: conntrack %p has no master\n", ct);
+ return ret;
+ }
+
+ read_lock_bh(&nf_conntrack_lock);
+ master_help = nfct_help(ct->master);
+ if (!master_help || !master_help->helper) {
+ DEBUGP("xt_helper: master ct %p has no helper\n",
+ exp->expectant);
+ goto out_unlock;
+ }
+
+ DEBUGP("master's name = %s , info->name = %s\n",
+ ct->master->helper->name, info->name);
+
+ if (info->name[0] == '\0')
+ ret ^= 1;
+ else
+ ret ^= !strncmp(master_help->helper->name, info->name,
+ strlen(master_help->helper->name));
+out_unlock:
+ read_unlock_bh(&nf_conntrack_lock);
+ return ret;
+}
+#endif
+
+static int check(const char *tablename,
+ const void *inf,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ struct xt_helper_info *info = matchinfo;
+
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ if (nf_ct_l3proto_try_module_get(match->family) < 0) {
+ printk(KERN_WARNING "can't load nf_conntrack support for "
+ "proto=%d\n", match->family);
+ return 0;
+ }
+#endif
+ info->name[29] = '\0';
+ return 1;
+}
+
+static void
+destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ nf_ct_l3proto_module_put(match->family);
+#endif
+}
+
+static struct xt_match helper_match = {
+ .name = "helper",
+ .match = match,
+ .matchsize = sizeof(struct xt_helper_info),
+ .checkentry = check,
+ .destroy = destroy,
+ .family = AF_INET,
+ .me = THIS_MODULE,
+};
+static struct xt_match helper6_match = {
+ .name = "helper",
+ .match = match,
+ .matchsize = sizeof(struct xt_helper_info),
+ .checkentry = check,
+ .destroy = destroy,
+ .family = AF_INET6,
+ .me = THIS_MODULE,
+};
+
+static int __init xt_helper_init(void)
+{
+ int ret;
+ need_conntrack();
+
+ ret = xt_register_match(&helper_match);
+ if (ret < 0)
+ return ret;
+
+ ret = xt_register_match(&helper6_match);
+ if (ret < 0)
+ xt_unregister_match(&helper_match);
+
+ return ret;
+}
+
+static void __exit xt_helper_fini(void)
+{
+ xt_unregister_match(&helper_match);
+ xt_unregister_match(&helper6_match);
+}
+
+module_init(xt_helper_init);
+module_exit(xt_helper_fini);
+
git://git.onelab.eu / linux-2.6.git / blobdiff