[NETFILTER]: x_tables: remove unused argument to target functions
[deliverable/linux.git] / net / ipv4 / netfilter / ip_nat_rule.c
CommitLineData
1da177e4
LT
1/* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9/* Everything about the rules for NAT. */
10#include <linux/types.h>
11#include <linux/ip.h>
12#include <linux/netfilter.h>
13#include <linux/netfilter_ipv4.h>
14#include <linux/module.h>
15#include <linux/kmod.h>
16#include <linux/skbuff.h>
17#include <linux/proc_fs.h>
18#include <net/checksum.h>
19#include <net/route.h>
20#include <linux/bitops.h>
21
e45b1be8
PM
22#define ASSERT_READ_LOCK(x)
23#define ASSERT_WRITE_LOCK(x)
1da177e4
LT
24
25#include <linux/netfilter_ipv4/ip_tables.h>
26#include <linux/netfilter_ipv4/ip_nat.h>
27#include <linux/netfilter_ipv4/ip_nat_core.h>
28#include <linux/netfilter_ipv4/ip_nat_rule.h>
29#include <linux/netfilter_ipv4/listhelp.h>
30
31#if 0
32#define DEBUGP printk
33#else
34#define DEBUGP(format, args...)
35#endif
36
37#define NAT_VALID_HOOKS ((1<<NF_IP_PRE_ROUTING) | (1<<NF_IP_POST_ROUTING) | (1<<NF_IP_LOCAL_OUT))
38
39static struct
40{
41 struct ipt_replace repl;
42 struct ipt_standard entries[3];
43 struct ipt_error term;
44} nat_initial_table __initdata
45= { { "nat", NAT_VALID_HOOKS, 4,
46 sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
47 { [NF_IP_PRE_ROUTING] = 0,
48 [NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
49 [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
50 { [NF_IP_PRE_ROUTING] = 0,
51 [NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
52 [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
53 0, NULL, { } },
54 {
55 /* PRE_ROUTING */
56 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
57 0,
58 sizeof(struct ipt_entry),
59 sizeof(struct ipt_standard),
60 0, { 0, 0 }, { } },
61 { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
62 -NF_ACCEPT - 1 } },
63 /* POST_ROUTING */
64 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
65 0,
66 sizeof(struct ipt_entry),
67 sizeof(struct ipt_standard),
68 0, { 0, 0 }, { } },
69 { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
70 -NF_ACCEPT - 1 } },
71 /* LOCAL_OUT */
72 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
73 0,
74 sizeof(struct ipt_entry),
75 sizeof(struct ipt_standard),
76 0, { 0, 0 }, { } },
77 { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
78 -NF_ACCEPT - 1 } }
79 },
80 /* ERROR */
81 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
82 0,
83 sizeof(struct ipt_entry),
84 sizeof(struct ipt_error),
85 0, { 0, 0 }, { } },
86 { { { { IPT_ALIGN(sizeof(struct ipt_error_target)), IPT_ERROR_TARGET } },
87 { } },
88 "ERROR"
89 }
90 }
91};
92
93static struct ipt_table nat_table = {
94 .name = "nat",
95 .valid_hooks = NAT_VALID_HOOKS,
96 .lock = RW_LOCK_UNLOCKED,
97 .me = THIS_MODULE,
2e4e6a17 98 .af = AF_INET,
1da177e4
LT
99};
100
101/* Source NAT */
102static unsigned int ipt_snat_target(struct sk_buff **pskb,
103 const struct net_device *in,
104 const struct net_device *out,
105 unsigned int hooknum,
c4986734 106 const struct ipt_target *target,
fe1cb108 107 const void *targinfo)
1da177e4
LT
108{
109 struct ip_conntrack *ct;
110 enum ip_conntrack_info ctinfo;
111 const struct ip_nat_multi_range_compat *mr = targinfo;
112
113 IP_NF_ASSERT(hooknum == NF_IP_POST_ROUTING);
114
115 ct = ip_conntrack_get(*pskb, &ctinfo);
116
117 /* Connection must be valid and new. */
118 IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED
119 || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
120 IP_NF_ASSERT(out);
121
122 return ip_nat_setup_info(ct, &mr->range[0], hooknum);
123}
124
125/* Before 2.6.11 we did implicit source NAT if required. Warn about change. */
126static void warn_if_extra_mangle(u32 dstip, u32 srcip)
127{
128 static int warned = 0;
129 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dstip } } };
130 struct rtable *rt;
131
132 if (ip_route_output_key(&rt, &fl) != 0)
133 return;
134
135 if (rt->rt_src != srcip && !warned) {
136 printk("NAT: no longer support implicit source local NAT\n");
137 printk("NAT: packet src %u.%u.%u.%u -> dst %u.%u.%u.%u\n",
138 NIPQUAD(srcip), NIPQUAD(dstip));
139 warned = 1;
140 }
141 ip_rt_put(rt);
142}
143
144static unsigned int ipt_dnat_target(struct sk_buff **pskb,
145 const struct net_device *in,
146 const struct net_device *out,
147 unsigned int hooknum,
c4986734 148 const struct ipt_target *target,
fe1cb108 149 const void *targinfo)
1da177e4
LT
150{
151 struct ip_conntrack *ct;
152 enum ip_conntrack_info ctinfo;
153 const struct ip_nat_multi_range_compat *mr = targinfo;
154
155 IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
156 || hooknum == NF_IP_LOCAL_OUT);
157
158 ct = ip_conntrack_get(*pskb, &ctinfo);
159
160 /* Connection must be valid and new. */
161 IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
162
163 if (hooknum == NF_IP_LOCAL_OUT
164 && mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)
165 warn_if_extra_mangle((*pskb)->nh.iph->daddr,
166 mr->range[0].min_ip);
167
168 return ip_nat_setup_info(ct, &mr->range[0], hooknum);
169}
170
171static int ipt_snat_checkentry(const char *tablename,
2e4e6a17 172 const void *entry,
c4986734 173 const struct ipt_target *target,
1da177e4
LT
174 void *targinfo,
175 unsigned int targinfosize,
176 unsigned int hook_mask)
177{
178 struct ip_nat_multi_range_compat *mr = targinfo;
179
180 /* Must be a valid range */
181 if (mr->rangesize != 1) {
182 printk("SNAT: multiple ranges no longer supported\n");
183 return 0;
184 }
1da177e4
LT
185 return 1;
186}
187
188static int ipt_dnat_checkentry(const char *tablename,
2e4e6a17 189 const void *entry,
c4986734 190 const struct ipt_target *target,
1da177e4
LT
191 void *targinfo,
192 unsigned int targinfosize,
193 unsigned int hook_mask)
194{
195 struct ip_nat_multi_range_compat *mr = targinfo;
196
197 /* Must be a valid range */
198 if (mr->rangesize != 1) {
199 printk("DNAT: multiple ranges no longer supported\n");
200 return 0;
201 }
1da177e4
LT
202 return 1;
203}
204
205inline unsigned int
206alloc_null_binding(struct ip_conntrack *conntrack,
207 struct ip_nat_info *info,
208 unsigned int hooknum)
209{
210 /* Force range to this IP; let proto decide mapping for
211 per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
212 Use reply in case it's already been mangled (eg local packet).
213 */
214 u_int32_t ip
215 = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
216 ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
217 : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
218 struct ip_nat_range range
219 = { IP_NAT_RANGE_MAP_IPS, ip, ip, { 0 }, { 0 } };
220
221 DEBUGP("Allocating NULL binding for %p (%u.%u.%u.%u)\n", conntrack,
222 NIPQUAD(ip));
223 return ip_nat_setup_info(conntrack, &range, hooknum);
224}
225
03486a4f
PM
226unsigned int
227alloc_null_binding_confirmed(struct ip_conntrack *conntrack,
228 struct ip_nat_info *info,
229 unsigned int hooknum)
230{
231 u_int32_t ip
232 = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
233 ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
234 : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
235 u_int16_t all
236 = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
237 ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all
238 : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all);
239 struct ip_nat_range range
240 = { IP_NAT_RANGE_MAP_IPS, ip, ip, { all }, { all } };
241
242 DEBUGP("Allocating NULL binding for confirmed %p (%u.%u.%u.%u)\n",
243 conntrack, NIPQUAD(ip));
244 return ip_nat_setup_info(conntrack, &range, hooknum);
245}
246
1da177e4
LT
247int ip_nat_rule_find(struct sk_buff **pskb,
248 unsigned int hooknum,
249 const struct net_device *in,
250 const struct net_device *out,
251 struct ip_conntrack *ct,
252 struct ip_nat_info *info)
253{
254 int ret;
255
fe1cb108 256 ret = ipt_do_table(pskb, hooknum, in, out, &nat_table);
1da177e4
LT
257
258 if (ret == NF_ACCEPT) {
259 if (!ip_nat_initialized(ct, HOOK2MANIP(hooknum)))
260 /* NUL mapping */
261 ret = alloc_null_binding(ct, info, hooknum);
262 }
263 return ret;
264}
265
266static struct ipt_target ipt_snat_reg = {
267 .name = "SNAT",
268 .target = ipt_snat_target,
1d5cd909
PM
269 .targetsize = sizeof(struct ip_nat_multi_range_compat),
270 .table = "nat",
271 .hooks = 1 << NF_IP_POST_ROUTING,
1da177e4
LT
272 .checkentry = ipt_snat_checkentry,
273};
274
275static struct ipt_target ipt_dnat_reg = {
276 .name = "DNAT",
277 .target = ipt_dnat_target,
1d5cd909
PM
278 .targetsize = sizeof(struct ip_nat_multi_range_compat),
279 .table = "nat",
19910d1a 280 .hooks = (1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT),
1da177e4
LT
281 .checkentry = ipt_dnat_checkentry,
282};
283
284int __init ip_nat_rule_init(void)
285{
286 int ret;
287
288 ret = ipt_register_table(&nat_table, &nat_initial_table.repl);
289 if (ret != 0)
290 return ret;
291 ret = ipt_register_target(&ipt_snat_reg);
292 if (ret != 0)
293 goto unregister_table;
294
295 ret = ipt_register_target(&ipt_dnat_reg);
296 if (ret != 0)
297 goto unregister_snat;
298
299 return ret;
300
301 unregister_snat:
302 ipt_unregister_target(&ipt_snat_reg);
303 unregister_table:
304 ipt_unregister_table(&nat_table);
305
306 return ret;
307}
308
309void ip_nat_rule_cleanup(void)
310{
311 ipt_unregister_target(&ipt_dnat_reg);
312 ipt_unregister_target(&ipt_snat_reg);
313 ipt_unregister_table(&nat_table);
314}
This page took 0.170737 seconds and 5 git commands to generate.