patch-2.4.20 linux-2.4.20/net/ipv4/netfilter/ipt_helper.c
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- Lines: 113
- Date:
Thu Nov 28 15:53:15 2002
- Orig file:
linux-2.4.19/net/ipv4/netfilter/ipt_helper.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -urN linux-2.4.19/net/ipv4/netfilter/ipt_helper.c linux-2.4.20/net/ipv4/netfilter/ipt_helper.c
@@ -0,0 +1,112 @@
+/*
+ * iptables module to match on related connections
+ * (c) 2001 Martin Josefsson <gandalf@wlug.westbo.se>
+ *
+ * Released under the terms of GNU GPLv2.
+ *
+ * 19 Mar 2002 Harald Welte <laforge@gnumonks.org>:
+ * - Port to newnat infrastructure
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_helper.h>
+
+MODULE_LICENSE("GPL");
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *matchinfo,
+ int offset,
+ const void *hdr,
+ u_int16_t datalen,
+ int *hotdrop)
+{
+ const struct ipt_helper_info *info = matchinfo;
+ struct ip_conntrack_expect *exp;
+ struct ip_conntrack *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
+ if (!ct) {
+ DEBUGP("ipt_helper: Eek! invalid conntrack?\n");
+ return 0;
+ }
+
+ if (!ct->master) {
+ DEBUGP("ipt_helper: conntrack %p has no master\n", ct);
+ return 0;
+ }
+
+ exp = ct->master;
+ if (!exp->expectant) {
+ DEBUGP("ipt_helper: expectation %p without expectant !?!\n",
+ exp);
+ return 0;
+ }
+
+ if (!exp->expectant->helper) {
+ DEBUGP("ipt_helper: master ct %p has no helper\n",
+ exp->expectant);
+ return 0;
+ }
+
+ DEBUGP("master's name = %s , info->name = %s\n",
+ exp->expectant->helper->name, info->name);
+
+ return !strncmp(exp->expectant->helper->name, info->name,
+ strlen(exp->expectant->helper->name)) ^ info->invert;
+}
+
+static int check(const char *tablename,
+ const struct ipt_ip *ip,
+ void *matchinfo,
+ unsigned int matchsize,
+ unsigned int hook_mask)
+{
+ struct ipt_helper_info *info = matchinfo;
+
+ info->name[29] = '\0';
+
+ /* verify size */
+ if (matchsize != IPT_ALIGN(sizeof(struct ipt_helper_info)))
+ return 0;
+
+ /* verify that we actually should match anything */
+ if ( strlen(info->name) == 0 )
+ return 0;
+
+ return 1;
+}
+
+static struct ipt_match helper_match
+= { { NULL, NULL }, "helper", &match, &check, NULL, THIS_MODULE };
+
+static int __init init(void)
+{
+ /* NULL if ip_conntrack not a module */
+ if (ip_conntrack_module)
+ __MOD_INC_USE_COUNT(ip_conntrack_module);
+ return ipt_register_match(&helper_match);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_match(&helper_match);
+ if (ip_conntrack_module)
+ __MOD_DEC_USE_COUNT(ip_conntrack_module);
+}
+
+module_init(init);
+module_exit(fini);
+
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