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12#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/udp.h>
15#include <linux/skbuff.h>
16#include <linux/in.h>
17
18#include <linux/netfilter/xt_multiport.h>
19#include <linux/netfilter/x_tables.h>
20#include <linux/netfilter_ipv4/ip_tables.h>
21#include <linux/netfilter_ipv6/ip6_tables.h>
22
23MODULE_LICENSE("GPL");
24MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
25MODULE_DESCRIPTION("Xtables: multiple port matching for TCP, UDP, UDP-Lite, SCTP and DCCP");
26MODULE_ALIAS("ipt_multiport");
27MODULE_ALIAS("ip6t_multiport");
28
29#if 0
30#define duprintf(format, args...) printk(format , ## args)
31#else
32#define duprintf(format, args...)
33#endif
34
35
36static inline bool
37ports_match_v0(const u_int16_t *portlist, enum xt_multiport_flags flags,
38 u_int8_t count, u_int16_t src, u_int16_t dst)
39{
40 unsigned int i;
41 for (i = 0; i < count; i++) {
42 if (flags != XT_MULTIPORT_DESTINATION && portlist[i] == src)
43 return true;
44
45 if (flags != XT_MULTIPORT_SOURCE && portlist[i] == dst)
46 return true;
47 }
48
49 return false;
50}
51
52
53static inline bool
54ports_match_v1(const struct xt_multiport_v1 *minfo,
55 u_int16_t src, u_int16_t dst)
56{
57 unsigned int i;
58 u_int16_t s, e;
59
60 for (i = 0; i < minfo->count; i++) {
61 s = minfo->ports[i];
62
63 if (minfo->pflags[i]) {
64
65 e = minfo->ports[++i];
66 duprintf("src or dst matches with %d-%d?\n", s, e);
67
68 if (minfo->flags == XT_MULTIPORT_SOURCE
69 && src >= s && src <= e)
70 return true ^ minfo->invert;
71 if (minfo->flags == XT_MULTIPORT_DESTINATION
72 && dst >= s && dst <= e)
73 return true ^ minfo->invert;
74 if (minfo->flags == XT_MULTIPORT_EITHER
75 && ((dst >= s && dst <= e)
76 || (src >= s && src <= e)))
77 return true ^ minfo->invert;
78 } else {
79
80 duprintf("src or dst matches with %d?\n", s);
81
82 if (minfo->flags == XT_MULTIPORT_SOURCE
83 && src == s)
84 return true ^ minfo->invert;
85 if (minfo->flags == XT_MULTIPORT_DESTINATION
86 && dst == s)
87 return true ^ minfo->invert;
88 if (minfo->flags == XT_MULTIPORT_EITHER
89 && (src == s || dst == s))
90 return true ^ minfo->invert;
91 }
92 }
93
94 return minfo->invert;
95}
96
97static bool
98multiport_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
99{
100 const __be16 *pptr;
101 __be16 _ports[2];
102 const struct xt_multiport *multiinfo = par->matchinfo;
103
104 if (par->fragoff != 0)
105 return false;
106
107 pptr = skb_header_pointer(skb, par->thoff, sizeof(_ports), _ports);
108 if (pptr == NULL) {
109
110
111
112 duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");
113 *par->hotdrop = true;
114 return false;
115 }
116
117 return ports_match_v0(multiinfo->ports, multiinfo->flags,
118 multiinfo->count, ntohs(pptr[0]), ntohs(pptr[1]));
119}
120
121static bool
122multiport_mt(const struct sk_buff *skb, const struct xt_match_param *par)
123{
124 const __be16 *pptr;
125 __be16 _ports[2];
126 const struct xt_multiport_v1 *multiinfo = par->matchinfo;
127
128 if (par->fragoff != 0)
129 return false;
130
131 pptr = skb_header_pointer(skb, par->thoff, sizeof(_ports), _ports);
132 if (pptr == NULL) {
133
134
135
136 duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");
137 *par->hotdrop = true;
138 return false;
139 }
140
141 return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
142}
143
144static inline bool
145check(u_int16_t proto,
146 u_int8_t ip_invflags,
147 u_int8_t match_flags,
148 u_int8_t count)
149{
150
151 return (proto == IPPROTO_TCP || proto == IPPROTO_UDP
152 || proto == IPPROTO_UDPLITE
153 || proto == IPPROTO_SCTP || proto == IPPROTO_DCCP)
154 && !(ip_invflags & XT_INV_PROTO)
155 && (match_flags == XT_MULTIPORT_SOURCE
156 || match_flags == XT_MULTIPORT_DESTINATION
157 || match_flags == XT_MULTIPORT_EITHER)
158 && count <= XT_MULTI_PORTS;
159}
160
161static bool multiport_mt_check_v0(const struct xt_mtchk_param *par)
162{
163 const struct ipt_ip *ip = par->entryinfo;
164 const struct xt_multiport *multiinfo = par->matchinfo;
165
166 return check(ip->proto, ip->invflags, multiinfo->flags,
167 multiinfo->count);
168}
169
170static bool multiport_mt_check(const struct xt_mtchk_param *par)
171{
172 const struct ipt_ip *ip = par->entryinfo;
173 const struct xt_multiport_v1 *multiinfo = par->matchinfo;
174
175 return check(ip->proto, ip->invflags, multiinfo->flags,
176 multiinfo->count);
177}
178
179static bool multiport_mt6_check_v0(const struct xt_mtchk_param *par)
180{
181 const struct ip6t_ip6 *ip = par->entryinfo;
182 const struct xt_multiport *multiinfo = par->matchinfo;
183
184 return check(ip->proto, ip->invflags, multiinfo->flags,
185 multiinfo->count);
186}
187
188static bool multiport_mt6_check(const struct xt_mtchk_param *par)
189{
190 const struct ip6t_ip6 *ip = par->entryinfo;
191 const struct xt_multiport_v1 *multiinfo = par->matchinfo;
192
193 return check(ip->proto, ip->invflags, multiinfo->flags,
194 multiinfo->count);
195}
196
197static struct xt_match multiport_mt_reg[] __read_mostly = {
198 {
199 .name = "multiport",
200 .family = NFPROTO_IPV4,
201 .revision = 0,
202 .checkentry = multiport_mt_check_v0,
203 .match = multiport_mt_v0,
204 .matchsize = sizeof(struct xt_multiport),
205 .me = THIS_MODULE,
206 },
207 {
208 .name = "multiport",
209 .family = NFPROTO_IPV4,
210 .revision = 1,
211 .checkentry = multiport_mt_check,
212 .match = multiport_mt,
213 .matchsize = sizeof(struct xt_multiport_v1),
214 .me = THIS_MODULE,
215 },
216 {
217 .name = "multiport",
218 .family = NFPROTO_IPV6,
219 .revision = 0,
220 .checkentry = multiport_mt6_check_v0,
221 .match = multiport_mt_v0,
222 .matchsize = sizeof(struct xt_multiport),
223 .me = THIS_MODULE,
224 },
225 {
226 .name = "multiport",
227 .family = NFPROTO_IPV6,
228 .revision = 1,
229 .checkentry = multiport_mt6_check,
230 .match = multiport_mt,
231 .matchsize = sizeof(struct xt_multiport_v1),
232 .me = THIS_MODULE,
233 },
234};
235
236static int __init multiport_mt_init(void)
237{
238 return xt_register_matches(multiport_mt_reg,
239 ARRAY_SIZE(multiport_mt_reg));
240}
241
242static void __exit multiport_mt_exit(void)
243{
244 xt_unregister_matches(multiport_mt_reg, ARRAY_SIZE(multiport_mt_reg));
245}
246
247module_init(multiport_mt_init);
248module_exit(multiport_mt_exit);
249
