--- /dev/null
+/*
+ * (C) 2000-2001 Svenning Soerensen <svenning@post5.tele.dk>
+ * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * 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.
+ */
+
+#include <linux/ip.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/ipv6.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter/x_tables.h>
+#include <net/netfilter/nf_nat.h>
+
+static unsigned int
+netmap_tg6(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct nf_nat_range *range = par->targinfo;
+ struct nf_nat_range newrange;
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ union nf_inet_addr new_addr, netmask;
+ unsigned int i;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ for (i = 0; i < ARRAY_SIZE(range->min_addr.ip6); i++)
+ netmask.ip6[i] = ~(range->min_addr.ip6[i] ^
+ range->max_addr.ip6[i]);
+
+ if (par->hooknum == NF_INET_PRE_ROUTING ||
+ par->hooknum == NF_INET_LOCAL_OUT)
+ new_addr.in6 = ipv6_hdr(skb)->daddr;
+ else
+ new_addr.in6 = ipv6_hdr(skb)->saddr;
+
+ for (i = 0; i < ARRAY_SIZE(new_addr.ip6); i++) {
+ new_addr.ip6[i] &= ~netmask.ip6[i];
+ new_addr.ip6[i] |= range->min_addr.ip6[i] &
+ netmask.ip6[i];
+ }
+
+ newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS;
+ newrange.min_addr = new_addr;
+ newrange.max_addr = new_addr;
+ newrange.min_proto = range->min_proto;
+ newrange.max_proto = range->max_proto;
+
+ return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
+}
+
+static int netmap_tg6_checkentry(const struct xt_tgchk_param *par)
+{
+ const struct nf_nat_range *range = par->targinfo;
+
+ if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
+ return -EINVAL;
+ return 0;
+}
+
+static unsigned int
+netmap_tg4(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ __be32 new_ip, netmask;
+ const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+ struct nf_nat_range newrange;
+
+ NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
+ par->hooknum == NF_INET_POST_ROUTING ||
+ par->hooknum == NF_INET_LOCAL_OUT ||
+ par->hooknum == NF_INET_LOCAL_IN);
+ ct = nf_ct_get(skb, &ctinfo);
+
+ netmask = ~(mr->range[0].min_ip ^ mr->range[0].max_ip);
+
+ if (par->hooknum == NF_INET_PRE_ROUTING ||
+ par->hooknum == NF_INET_LOCAL_OUT)
+ new_ip = ip_hdr(skb)->daddr & ~netmask;
+ else
+ new_ip = ip_hdr(skb)->saddr & ~netmask;
+ new_ip |= mr->range[0].min_ip & netmask;
+
+ memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
+ memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
+ newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
+ newrange.min_addr.ip = new_ip;
+ newrange.max_addr.ip = new_ip;
+ newrange.min_proto = mr->range[0].min;
+ newrange.max_proto = mr->range[0].max;
+
+ /* Hand modified range to generic setup. */
+ return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
+}
+
+static int netmap_tg4_check(const struct xt_tgchk_param *par)
+{
+ const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+
+ if (!(mr->range[0].flags & NF_NAT_RANGE_MAP_IPS)) {
+ pr_debug("bad MAP_IPS.\n");
+ return -EINVAL;
+ }
+ if (mr->rangesize != 1) {
+ pr_debug("bad rangesize %u.\n", mr->rangesize);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static struct xt_target netmap_tg_reg[] __read_mostly = {
+ {
+ .name = "NETMAP",
+ .family = NFPROTO_IPV6,
+ .revision = 0,
+ .target = netmap_tg6,
+ .targetsize = sizeof(struct nf_nat_range),
+ .table = "nat",
+ .hooks = (1 << NF_INET_PRE_ROUTING) |
+ (1 << NF_INET_POST_ROUTING) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_LOCAL_IN),
+ .checkentry = netmap_tg6_checkentry,
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "NETMAP",
+ .family = NFPROTO_IPV4,
+ .revision = 0,
+ .target = netmap_tg4,
+ .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
+ .table = "nat",
+ .hooks = (1 << NF_INET_PRE_ROUTING) |
+ (1 << NF_INET_POST_ROUTING) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_LOCAL_IN),
+ .checkentry = netmap_tg4_check,
+ .me = THIS_MODULE,
+ },
+};
+
+static int __init netmap_tg_init(void)
+{
+ return xt_register_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
+}
+
+static void netmap_tg_exit(void)
+{
+ xt_unregister_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
+}
+
+module_init(netmap_tg_init);
+module_exit(netmap_tg_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of subnets");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS("ip6t_NETMAP");
+MODULE_ALIAS("ipt_NETMAP");
Code Review / kvmfornfv.git / blobdiff