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12#include <linux/types.h>
13#include <linux/timer.h>
14#include <linux/module.h>
15#include <linux/netfilter.h>
16#include <linux/in6.h>
17#include <linux/icmpv6.h>
18#include <linux/ipv6.h>
19#include <net/ipv6.h>
20#include <net/ip6_checksum.h>
21#include <linux/seq_file.h>
22#include <linux/netfilter_ipv6.h>
23#include <net/netfilter/nf_conntrack_tuple.h>
24#include <net/netfilter/nf_conntrack_l4proto.h>
25#include <net/netfilter/nf_conntrack_core.h>
26#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
27#include <net/netfilter/nf_log.h>
28
29static unsigned int nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
30
31static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
32 unsigned int dataoff,
33 struct nf_conntrack_tuple *tuple)
34{
35 const struct icmp6hdr *hp;
36 struct icmp6hdr _hdr;
37
38 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
39 if (hp == NULL)
40 return false;
41 tuple->dst.u.icmp.type = hp->icmp6_type;
42 tuple->src.u.icmp.id = hp->icmp6_identifier;
43 tuple->dst.u.icmp.code = hp->icmp6_code;
44
45 return true;
46}
47
48
49static const u_int8_t invmap[] = {
50 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
51 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
52 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1,
53 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY +1
54};
55
56static const u_int8_t noct_valid_new[] = {
57 [ICMPV6_MGM_QUERY - 130] = 1,
58 [ICMPV6_MGM_REPORT -130] = 1,
59 [ICMPV6_MGM_REDUCTION - 130] = 1,
60 [NDISC_ROUTER_SOLICITATION - 130] = 1,
61 [NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
62 [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
63 [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
64 [ICMPV6_MLD2_REPORT - 130] = 1
65};
66
67static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
68 const struct nf_conntrack_tuple *orig)
69{
70 int type = orig->dst.u.icmp.type - 128;
71 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
72 return false;
73
74 tuple->src.u.icmp.id = orig->src.u.icmp.id;
75 tuple->dst.u.icmp.type = invmap[type] - 1;
76 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
77 return true;
78}
79
80
81static int icmpv6_print_tuple(struct seq_file *s,
82 const struct nf_conntrack_tuple *tuple)
83{
84 return seq_printf(s, "type=%u code=%u id=%u ",
85 tuple->dst.u.icmp.type,
86 tuple->dst.u.icmp.code,
87 ntohs(tuple->src.u.icmp.id));
88}
89
90
91static int icmpv6_packet(struct nf_conn *ct,
92 const struct sk_buff *skb,
93 unsigned int dataoff,
94 enum ip_conntrack_info ctinfo,
95 u_int8_t pf,
96 unsigned int hooknum)
97{
98
99
100
101 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
102
103 return NF_ACCEPT;
104}
105
106
107static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
108 unsigned int dataoff)
109{
110 static const u_int8_t valid_new[] = {
111 [ICMPV6_ECHO_REQUEST - 128] = 1,
112 [ICMPV6_NI_QUERY - 128] = 1
113 };
114 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
115
116 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
117
118 pr_debug("icmpv6: can't create new conn with type %u\n",
119 type + 128);
120 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
121 if (LOG_INVALID(nf_ct_net(ct), IPPROTO_ICMPV6))
122 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
123 "nf_ct_icmpv6: invalid new with type %d ",
124 type + 128);
125 return false;
126 }
127 return true;
128}
129
130static int
131icmpv6_error_message(struct net *net,
132 struct sk_buff *skb,
133 unsigned int icmp6off,
134 enum ip_conntrack_info *ctinfo,
135 unsigned int hooknum)
136{
137 struct nf_conntrack_tuple intuple, origtuple;
138 const struct nf_conntrack_tuple_hash *h;
139 const struct nf_conntrack_l4proto *inproto;
140
141 NF_CT_ASSERT(skb->nfct == NULL);
142
143
144 if (!nf_ct_get_tuplepr(skb,
145 skb_network_offset(skb)
146 + sizeof(struct ipv6hdr)
147 + sizeof(struct icmp6hdr),
148 PF_INET6, &origtuple)) {
149 pr_debug("icmpv6_error: Can't get tuple\n");
150 return -NF_ACCEPT;
151 }
152
153
154 inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
155
156
157
158 if (!nf_ct_invert_tuple(&intuple, &origtuple,
159 &nf_conntrack_l3proto_ipv6, inproto)) {
160 pr_debug("icmpv6_error: Can't invert tuple\n");
161 return -NF_ACCEPT;
162 }
163
164 *ctinfo = IP_CT_RELATED;
165
166 h = nf_conntrack_find_get(net, &intuple);
167 if (!h) {
168 pr_debug("icmpv6_error: no match\n");
169 return -NF_ACCEPT;
170 } else {
171 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
172 *ctinfo += IP_CT_IS_REPLY;
173 }
174
175
176 skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
177 skb->nfctinfo = *ctinfo;
178 return -NF_ACCEPT;
179}
180
181static int
182icmpv6_error(struct net *net, struct sk_buff *skb, unsigned int dataoff,
183 enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
184{
185 const struct icmp6hdr *icmp6h;
186 struct icmp6hdr _ih;
187 int type;
188
189 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
190 if (icmp6h == NULL) {
191 if (LOG_INVALID(net, IPPROTO_ICMPV6))
192 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
193 "nf_ct_icmpv6: short packet ");
194 return -NF_ACCEPT;
195 }
196
197 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
198 nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
199 if (LOG_INVALID(net, IPPROTO_ICMPV6))
200 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
201 "nf_ct_icmpv6: ICMPv6 checksum failed ");
202 return -NF_ACCEPT;
203 }
204
205 type = icmp6h->icmp6_type - 130;
206 if (type >= 0 && type < sizeof(noct_valid_new) &&
207 noct_valid_new[type]) {
208 skb->nfct = &nf_conntrack_untracked.ct_general;
209 skb->nfctinfo = IP_CT_NEW;
210 nf_conntrack_get(skb->nfct);
211 return NF_ACCEPT;
212 }
213
214
215 if (icmp6h->icmp6_type >= 128)
216 return NF_ACCEPT;
217
218 return icmpv6_error_message(net, skb, dataoff, ctinfo, hooknum);
219}
220
221#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
222
223#include <linux/netfilter/nfnetlink.h>
224#include <linux/netfilter/nfnetlink_conntrack.h>
225static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
226 const struct nf_conntrack_tuple *t)
227{
228 NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
229 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
230 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
231
232 return 0;
233
234nla_put_failure:
235 return -1;
236}
237
238static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
239 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
240 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
241 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
242};
243
244static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
245 struct nf_conntrack_tuple *tuple)
246{
247 if (!tb[CTA_PROTO_ICMPV6_TYPE]
248 || !tb[CTA_PROTO_ICMPV6_CODE]
249 || !tb[CTA_PROTO_ICMPV6_ID])
250 return -EINVAL;
251
252 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
253 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
254 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
255
256 if (tuple->dst.u.icmp.type < 128
257 || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
258 || !invmap[tuple->dst.u.icmp.type - 128])
259 return -EINVAL;
260
261 return 0;
262}
263
264static int icmpv6_nlattr_tuple_size(void)
265{
266 return nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
267}
268#endif
269
270#ifdef CONFIG_SYSCTL
271static struct ctl_table_header *icmpv6_sysctl_header;
272static struct ctl_table icmpv6_sysctl_table[] = {
273 {
274 .procname = "nf_conntrack_icmpv6_timeout",
275 .data = &nf_ct_icmpv6_timeout,
276 .maxlen = sizeof(unsigned int),
277 .mode = 0644,
278 .proc_handler = proc_dointvec_jiffies,
279 },
280 {
281 .ctl_name = 0
282 }
283};
284#endif
285
286struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
287{
288 .l3proto = PF_INET6,
289 .l4proto = IPPROTO_ICMPV6,
290 .name = "icmpv6",
291 .pkt_to_tuple = icmpv6_pkt_to_tuple,
292 .invert_tuple = icmpv6_invert_tuple,
293 .print_tuple = icmpv6_print_tuple,
294 .packet = icmpv6_packet,
295 .new = icmpv6_new,
296 .error = icmpv6_error,
297#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
298 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
299 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
300 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
301 .nla_policy = icmpv6_nla_policy,
302#endif
303#ifdef CONFIG_SYSCTL
304 .ctl_table_header = &icmpv6_sysctl_header,
305 .ctl_table = icmpv6_sysctl_table,
306#endif
307};
308
