patch-2.3.99-pre2 linux/net/ipv4/netfilter/ipt_REDIRECT.c
Next file: linux/net/ipv4/netfilter/ipt_REJECT.c
Previous file: linux/net/ipv4/netfilter/ipt_MIRROR.c
Back to the patch index
Back to the overall index
- Lines: 105
- Date:
Fri Mar 17 10:56:20 2000
- Orig file:
v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_REDIRECT.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_REDIRECT.c linux/net/ipv4/netfilter/ipt_REDIRECT.c
@@ -0,0 +1,104 @@
+/* Redirect. Simple mapping which alters dst to a local IP address. */
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/netdevice.h>
+#include <linux/if.h>
+#include <linux/inetdevice.h>
+#include <net/protocol.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+
+EXPORT_NO_SYMBOLS;
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/* FIXME: Take multiple ranges --RR */
+static int
+redirect_check(const char *tablename,
+ const struct ipt_entry *e,
+ void *targinfo,
+ unsigned int targinfosize,
+ unsigned int hook_mask)
+{
+ const struct ip_nat_multi_range *mr = targinfo;
+
+ if (targinfosize != IPT_ALIGN(sizeof(*mr))) {
+ DEBUGP("redirect_check: size %u.\n", targinfosize);
+ return 0;
+ }
+ if (hook_mask & ~((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT))) {
+ DEBUGP("redirect_check: bad hooks %x.\n", hook_mask);
+ return 0;
+ }
+ if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+ DEBUGP("redirect_check: bad MAP_IPS.\n");
+ return 0;
+ }
+ if (mr->rangesize != 1) {
+ DEBUGP("redirect_check: bad rangesize %u.\n", mr->rangesize);
+ return 0;
+ }
+ return 1;
+}
+
+static unsigned int
+redirect_target(struct sk_buff **pskb,
+ unsigned int hooknum,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *targinfo,
+ void *userinfo)
+{
+ struct ip_conntrack *ct;
+ enum ip_conntrack_info ctinfo;
+ u_int32_t newdst;
+ const struct ip_nat_range *r = targinfo;
+ struct ip_nat_multi_range newrange;
+
+ IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
+ || hooknum == NF_IP_LOCAL_OUT);
+
+ ct = ip_conntrack_get(*pskb, &ctinfo);
+ IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
+
+ /* Local packets: make them go to loopback */
+ if (hooknum == NF_IP_LOCAL_OUT)
+ newdst = htonl(0x7F000001);
+ else
+ /* Grab first address on interface. */
+ newdst = (((struct in_device *)(*pskb)->dev->ip_ptr)
+ ->ifa_list->ifa_local);
+
+ /* Transfer from original range. */
+ newrange = ((struct ip_nat_multi_range)
+ { 1, { { r->flags | IP_NAT_RANGE_MAP_IPS,
+ newdst, newdst,
+ r->min, r->max } } });
+
+ /* Hand modified range to generic setup. */
+ return ip_nat_setup_info(ct, &newrange, hooknum);
+}
+
+static struct ipt_target redirect_reg
+= { { NULL, NULL }, "REDIRECT", redirect_target, redirect_check, THIS_MODULE };
+
+static int __init init(void)
+{
+ return ipt_register_target(&redirect_reg);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_target(&redirect_reg);
+}
+
+module_init(init);
+module_exit(fini);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)