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23#include <linux/module.h>
24#include <linux/skbuff.h>
25#include <net/netfilter/nf_conntrack.h>
26#include <net/netfilter/nf_conntrack_ecache.h>
27#include <linux/netfilter/x_tables.h>
28#include <linux/netfilter/xt_connmark.h>
29
30MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
31MODULE_DESCRIPTION("Xtables: connection mark operations");
32MODULE_LICENSE("GPL");
33MODULE_ALIAS("ipt_CONNMARK");
34MODULE_ALIAS("ip6t_CONNMARK");
35MODULE_ALIAS("ipt_connmark");
36MODULE_ALIAS("ip6t_connmark");
37
38static unsigned int
39connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
40{
41 enum ip_conntrack_info ctinfo;
42 u_int32_t new_targetmark;
43 struct nf_conn *ct;
44 u_int32_t newmark;
45
46 ct = nf_ct_get(skb, &ctinfo);
47 if (ct == NULL)
48 return XT_CONTINUE;
49
50 switch (info->mode) {
51 case XT_CONNMARK_SET:
52 newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
53 if (info->shift_dir == D_SHIFT_RIGHT)
54 newmark >>= info->shift_bits;
55 else
56 newmark <<= info->shift_bits;
57
58 if (ct->mark != newmark) {
59 ct->mark = newmark;
60 nf_conntrack_event_cache(IPCT_MARK, ct);
61 }
62 break;
63 case XT_CONNMARK_SAVE:
64 new_targetmark = (skb->mark & info->nfmask);
65 if (info->shift_dir == D_SHIFT_RIGHT)
66 new_targetmark >>= info->shift_bits;
67 else
68 new_targetmark <<= info->shift_bits;
69
70 newmark = (ct->mark & ~info->ctmask) ^
71 new_targetmark;
72 if (ct->mark != newmark) {
73 ct->mark = newmark;
74 nf_conntrack_event_cache(IPCT_MARK, ct);
75 }
76 break;
77 case XT_CONNMARK_RESTORE:
78 new_targetmark = (ct->mark & info->ctmask);
79 if (info->shift_dir == D_SHIFT_RIGHT)
80 new_targetmark >>= info->shift_bits;
81 else
82 new_targetmark <<= info->shift_bits;
83
84 newmark = (skb->mark & ~info->nfmask) ^
85 new_targetmark;
86 skb->mark = newmark;
87 break;
88 }
89 return XT_CONTINUE;
90}
91
92static unsigned int
93connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
94{
95 const struct xt_connmark_tginfo1 *info = par->targinfo;
96 const struct xt_connmark_tginfo2 info2 = {
97 .ctmark = info->ctmark,
98 .ctmask = info->ctmask,
99 .nfmask = info->nfmask,
100 .mode = info->mode,
101 };
102
103 return connmark_tg_shift(skb, &info2);
104}
105
106static unsigned int
107connmark_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
108{
109 const struct xt_connmark_tginfo2 *info = par->targinfo;
110
111 return connmark_tg_shift(skb, info);
112}
113
114static int connmark_tg_check(const struct xt_tgchk_param *par)
115{
116 int ret;
117
118 ret = nf_ct_netns_get(par->net, par->family);
119 if (ret < 0)
120 pr_info_ratelimited("cannot load conntrack support for proto=%u\n",
121 par->family);
122 return ret;
123}
124
125static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
126{
127 nf_ct_netns_put(par->net, par->family);
128}
129
130static bool
131connmark_mt(const struct sk_buff *skb, struct xt_action_param *par)
132{
133 const struct xt_connmark_mtinfo1 *info = par->matchinfo;
134 enum ip_conntrack_info ctinfo;
135 const struct nf_conn *ct;
136
137 ct = nf_ct_get(skb, &ctinfo);
138 if (ct == NULL)
139 return false;
140
141 return ((ct->mark & info->mask) == info->mark) ^ info->invert;
142}
143
144static int connmark_mt_check(const struct xt_mtchk_param *par)
145{
146 int ret;
147
148 ret = nf_ct_netns_get(par->net, par->family);
149 if (ret < 0)
150 pr_info_ratelimited("cannot load conntrack support for proto=%u\n",
151 par->family);
152 return ret;
153}
154
155static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
156{
157 nf_ct_netns_put(par->net, par->family);
158}
159
160static struct xt_target connmark_tg_reg[] __read_mostly = {
161 {
162 .name = "CONNMARK",
163 .revision = 1,
164 .family = NFPROTO_UNSPEC,
165 .checkentry = connmark_tg_check,
166 .target = connmark_tg,
167 .targetsize = sizeof(struct xt_connmark_tginfo1),
168 .destroy = connmark_tg_destroy,
169 .me = THIS_MODULE,
170 },
171 {
172 .name = "CONNMARK",
173 .revision = 2,
174 .family = NFPROTO_UNSPEC,
175 .checkentry = connmark_tg_check,
176 .target = connmark_tg_v2,
177 .targetsize = sizeof(struct xt_connmark_tginfo2),
178 .destroy = connmark_tg_destroy,
179 .me = THIS_MODULE,
180 }
181};
182
183static struct xt_match connmark_mt_reg __read_mostly = {
184 .name = "connmark",
185 .revision = 1,
186 .family = NFPROTO_UNSPEC,
187 .checkentry = connmark_mt_check,
188 .match = connmark_mt,
189 .matchsize = sizeof(struct xt_connmark_mtinfo1),
190 .destroy = connmark_mt_destroy,
191 .me = THIS_MODULE,
192};
193
194static int __init connmark_mt_init(void)
195{
196 int ret;
197
198 ret = xt_register_targets(connmark_tg_reg,
199 ARRAY_SIZE(connmark_tg_reg));
200 if (ret < 0)
201 return ret;
202 ret = xt_register_match(&connmark_mt_reg);
203 if (ret < 0) {
204 xt_unregister_targets(connmark_tg_reg,
205 ARRAY_SIZE(connmark_tg_reg));
206 return ret;
207 }
208 return 0;
209}
210
211static void __exit connmark_mt_exit(void)
212{
213 xt_unregister_match(&connmark_mt_reg);
214 xt_unregister_target(connmark_tg_reg);
215}
216
217module_init(connmark_mt_init);
218module_exit(connmark_mt_exit);
219
