ipvs: convert lblc scheduler to rcu
[linux-3.10.git] / net / netfilter / xt_NETMAP.c
1 /*
2  * (C) 2000-2001 Svenning Soerensen <svenning@post5.tele.dk>
3  * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9
10 #include <linux/ip.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/netdevice.h>
14 #include <linux/ipv6.h>
15 #include <linux/netfilter.h>
16 #include <linux/netfilter_ipv4.h>
17 #include <linux/netfilter_ipv6.h>
18 #include <linux/netfilter/x_tables.h>
19 #include <net/netfilter/nf_nat.h>
20
21 static unsigned int
22 netmap_tg6(struct sk_buff *skb, const struct xt_action_param *par)
23 {
24         const struct nf_nat_range *range = par->targinfo;
25         struct nf_nat_range newrange;
26         struct nf_conn *ct;
27         enum ip_conntrack_info ctinfo;
28         union nf_inet_addr new_addr, netmask;
29         unsigned int i;
30
31         ct = nf_ct_get(skb, &ctinfo);
32         for (i = 0; i < ARRAY_SIZE(range->min_addr.ip6); i++)
33                 netmask.ip6[i] = ~(range->min_addr.ip6[i] ^
34                                    range->max_addr.ip6[i]);
35
36         if (par->hooknum == NF_INET_PRE_ROUTING ||
37             par->hooknum == NF_INET_LOCAL_OUT)
38                 new_addr.in6 = ipv6_hdr(skb)->daddr;
39         else
40                 new_addr.in6 = ipv6_hdr(skb)->saddr;
41
42         for (i = 0; i < ARRAY_SIZE(new_addr.ip6); i++) {
43                 new_addr.ip6[i] &= ~netmask.ip6[i];
44                 new_addr.ip6[i] |= range->min_addr.ip6[i] &
45                                    netmask.ip6[i];
46         }
47
48         newrange.flags  = range->flags | NF_NAT_RANGE_MAP_IPS;
49         newrange.min_addr       = new_addr;
50         newrange.max_addr       = new_addr;
51         newrange.min_proto      = range->min_proto;
52         newrange.max_proto      = range->max_proto;
53
54         return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
55 }
56
57 static int netmap_tg6_checkentry(const struct xt_tgchk_param *par)
58 {
59         const struct nf_nat_range *range = par->targinfo;
60
61         if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
62                 return -EINVAL;
63         return 0;
64 }
65
66 static unsigned int
67 netmap_tg4(struct sk_buff *skb, const struct xt_action_param *par)
68 {
69         struct nf_conn *ct;
70         enum ip_conntrack_info ctinfo;
71         __be32 new_ip, netmask;
72         const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
73         struct nf_nat_range newrange;
74
75         NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
76                      par->hooknum == NF_INET_POST_ROUTING ||
77                      par->hooknum == NF_INET_LOCAL_OUT ||
78                      par->hooknum == NF_INET_LOCAL_IN);
79         ct = nf_ct_get(skb, &ctinfo);
80
81         netmask = ~(mr->range[0].min_ip ^ mr->range[0].max_ip);
82
83         if (par->hooknum == NF_INET_PRE_ROUTING ||
84             par->hooknum == NF_INET_LOCAL_OUT)
85                 new_ip = ip_hdr(skb)->daddr & ~netmask;
86         else
87                 new_ip = ip_hdr(skb)->saddr & ~netmask;
88         new_ip |= mr->range[0].min_ip & netmask;
89
90         memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
91         memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
92         newrange.flags       = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
93         newrange.min_addr.ip = new_ip;
94         newrange.max_addr.ip = new_ip;
95         newrange.min_proto   = mr->range[0].min;
96         newrange.max_proto   = mr->range[0].max;
97
98         /* Hand modified range to generic setup. */
99         return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
100 }
101
102 static int netmap_tg4_check(const struct xt_tgchk_param *par)
103 {
104         const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
105
106         if (!(mr->range[0].flags & NF_NAT_RANGE_MAP_IPS)) {
107                 pr_debug("bad MAP_IPS.\n");
108                 return -EINVAL;
109         }
110         if (mr->rangesize != 1) {
111                 pr_debug("bad rangesize %u.\n", mr->rangesize);
112                 return -EINVAL;
113         }
114         return 0;
115 }
116
117 static struct xt_target netmap_tg_reg[] __read_mostly = {
118         {
119                 .name       = "NETMAP",
120                 .family     = NFPROTO_IPV6,
121                 .revision   = 0,
122                 .target     = netmap_tg6,
123                 .targetsize = sizeof(struct nf_nat_range),
124                 .table      = "nat",
125                 .hooks      = (1 << NF_INET_PRE_ROUTING) |
126                               (1 << NF_INET_POST_ROUTING) |
127                               (1 << NF_INET_LOCAL_OUT) |
128                               (1 << NF_INET_LOCAL_IN),
129                 .checkentry = netmap_tg6_checkentry,
130                 .me         = THIS_MODULE,
131         },
132         {
133                 .name       = "NETMAP",
134                 .family     = NFPROTO_IPV4,
135                 .revision   = 0,
136                 .target     = netmap_tg4,
137                 .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
138                 .table      = "nat",
139                 .hooks      = (1 << NF_INET_PRE_ROUTING) |
140                               (1 << NF_INET_POST_ROUTING) |
141                               (1 << NF_INET_LOCAL_OUT) |
142                               (1 << NF_INET_LOCAL_IN),
143                 .checkentry = netmap_tg4_check,
144                 .me         = THIS_MODULE,
145         },
146 };
147
148 static int __init netmap_tg_init(void)
149 {
150         return xt_register_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
151 }
152
153 static void netmap_tg_exit(void)
154 {
155         xt_unregister_targets(netmap_tg_reg, ARRAY_SIZE(netmap_tg_reg));
156 }
157
158 module_init(netmap_tg_init);
159 module_exit(netmap_tg_exit);
160
161 MODULE_LICENSE("GPL");
162 MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of subnets");
163 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
164 MODULE_ALIAS("ip6t_NETMAP");
165 MODULE_ALIAS("ipt_NETMAP");