diff options
Diffstat (limited to 'net/netfilter/xt_NETMAP.c')
| -rw-r--r-- | net/netfilter/xt_NETMAP.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/net/netfilter/xt_NETMAP.c b/net/netfilter/xt_NETMAP.c new file mode 100644 index 0000000..b253e07 --- /dev/null +++ b/net/netfilter/xt_NETMAP.c @@ -0,0 +1,165 @@ +/* + * (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"); |
