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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/nf_conntrack_zones.h>
27#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
28#include <net/netfilter/nf_log.h>
29
30static unsigned int nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
31
32static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
33 unsigned int dataoff,
34 struct nf_conntrack_tuple *tuple)
35{
36 const struct icmp6hdr *hp;
37 struct icmp6hdr _hdr;
38
39 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
40 if (hp == NULL)
41 return false;
42 tuple->dst.u.icmp.type = hp->icmp6_type;
43 tuple->src.u.icmp.id = hp->icmp6_identifier;
44 tuple->dst.u.icmp.code = hp->icmp6_code;
45
46 return true;
47}
48
49
50static const u_int8_t invmap[] = {
51 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
52 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
53 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1,
54 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY +1
55};
56
57static const u_int8_t noct_valid_new[] = {
58 [ICMPV6_MGM_QUERY - 130] = 1,
59 [ICMPV6_MGM_REPORT -130] = 1,
60 [ICMPV6_MGM_REDUCTION - 130] = 1,
61 [NDISC_ROUTER_SOLICITATION - 130] = 1,
62 [NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
63 [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
64 [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
65 [ICMPV6_MLD2_REPORT - 130] = 1
66};
67
68static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
69 const struct nf_conntrack_tuple *orig)
70{
71 int type = orig->dst.u.icmp.type - 128;
72 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
73 return false;
74
75 tuple->src.u.icmp.id = orig->src.u.icmp.id;
76 tuple->dst.u.icmp.type = invmap[type] - 1;
77 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
78 return true;
79}
80
81
82static int icmpv6_print_tuple(struct seq_file *s,
83 const struct nf_conntrack_tuple *tuple)
84{
85 return seq_printf(s, "type=%u code=%u id=%u ",
86 tuple->dst.u.icmp.type,
87 tuple->dst.u.icmp.code,
88 ntohs(tuple->src.u.icmp.id));
89}
90
91
92static int icmpv6_packet(struct nf_conn *ct,
93 const struct sk_buff *skb,
94 unsigned int dataoff,
95 enum ip_conntrack_info ctinfo,
96 u_int8_t pf,
97 unsigned int hooknum)
98{
99
100
101
102 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
103
104 return NF_ACCEPT;
105}
106
107
108static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
109 unsigned int dataoff)
110{
111 static const u_int8_t valid_new[] = {
112 [ICMPV6_ECHO_REQUEST - 128] = 1,
113 [ICMPV6_NI_QUERY - 128] = 1
114 };
115 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
116
117 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
118
119 pr_debug("icmpv6: can't create new conn with type %u\n",
120 type + 128);
121 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
122 if (LOG_INVALID(nf_ct_net(ct), IPPROTO_ICMPV6))
123 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
124 "nf_ct_icmpv6: invalid new with type %d ",
125 type + 128);
126 return false;
127 }
128 return true;
129}
130
131static int
132icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
133 struct sk_buff *skb,
134 unsigned int icmp6off,
135 enum ip_conntrack_info *ctinfo,
136 unsigned int hooknum)
137{
138 struct nf_conntrack_tuple intuple, origtuple;
139 const struct nf_conntrack_tuple_hash *h;
140 const struct nf_conntrack_l4proto *inproto;
141 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
142
143 NF_CT_ASSERT(skb->nfct == NULL);
144
145
146 if (!nf_ct_get_tuplepr(skb,
147 skb_network_offset(skb)
148 + sizeof(struct ipv6hdr)
149 + sizeof(struct icmp6hdr),
150 PF_INET6, &origtuple)) {
151 pr_debug("icmpv6_error: Can't get tuple\n");
152 return -NF_ACCEPT;
153 }
154
155
156 inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
157
158
159
160 if (!nf_ct_invert_tuple(&intuple, &origtuple,
161 &nf_conntrack_l3proto_ipv6, inproto)) {
162 pr_debug("icmpv6_error: Can't invert tuple\n");
163 return -NF_ACCEPT;
164 }
165
166 *ctinfo = IP_CT_RELATED;
167
168 h = nf_conntrack_find_get(net, zone, &intuple);
169 if (!h) {
170 pr_debug("icmpv6_error: no match\n");
171 return -NF_ACCEPT;
172 } else {
173 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
174 *ctinfo += IP_CT_IS_REPLY;
175 }
176
177
178 skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
179 skb->nfctinfo = *ctinfo;
180 return NF_ACCEPT;
181}
182
183static int
184icmpv6_error(struct net *net, struct nf_conn *tmpl,
185 struct sk_buff *skb, unsigned int dataoff,
186 enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
187{
188 const struct icmp6hdr *icmp6h;
189 struct icmp6hdr _ih;
190 int type;
191
192 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
193 if (icmp6h == NULL) {
194 if (LOG_INVALID(net, IPPROTO_ICMPV6))
195 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
196 "nf_ct_icmpv6: short packet ");
197 return -NF_ACCEPT;
198 }
199
200 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
201 nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
202 if (LOG_INVALID(net, IPPROTO_ICMPV6))
203 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
204 "nf_ct_icmpv6: ICMPv6 checksum failed ");
205 return -NF_ACCEPT;
206 }
207
208 type = icmp6h->icmp6_type - 130;
209 if (type >= 0 && type < sizeof(noct_valid_new) &&
210 noct_valid_new[type]) {
211 skb->nfct = &nf_ct_untracked_get()->ct_general;
212 skb->nfctinfo = IP_CT_NEW;
213 nf_conntrack_get(skb->nfct);
214 return NF_ACCEPT;
215 }
216
217
218 if (icmp6h->icmp6_type >= 128)
219 return NF_ACCEPT;
220
221 return icmpv6_error_message(net, tmpl, skb, dataoff, ctinfo, hooknum);
222}
223
224#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
225
226#include <linux/netfilter/nfnetlink.h>
227#include <linux/netfilter/nfnetlink_conntrack.h>
228static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
229 const struct nf_conntrack_tuple *t)
230{
231 NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
232 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
233 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
234
235 return 0;
236
237nla_put_failure:
238 return -1;
239}
240
241static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
242 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
243 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
244 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
245};
246
247static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
248 struct nf_conntrack_tuple *tuple)
249{
250 if (!tb[CTA_PROTO_ICMPV6_TYPE] ||
251 !tb[CTA_PROTO_ICMPV6_CODE] ||
252 !tb[CTA_PROTO_ICMPV6_ID])
253 return -EINVAL;
254
255 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
256 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
257 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
258
259 if (tuple->dst.u.icmp.type < 128 ||
260 tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
261 !invmap[tuple->dst.u.icmp.type - 128])
262 return -EINVAL;
263
264 return 0;
265}
266
267static int icmpv6_nlattr_tuple_size(void)
268{
269 return nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
270}
271#endif
272
273#ifdef CONFIG_SYSCTL
274static struct ctl_table_header *icmpv6_sysctl_header;
275static struct ctl_table icmpv6_sysctl_table[] = {
276 {
277 .procname = "nf_conntrack_icmpv6_timeout",
278 .data = &nf_ct_icmpv6_timeout,
279 .maxlen = sizeof(unsigned int),
280 .mode = 0644,
281 .proc_handler = proc_dointvec_jiffies,
282 },
283 { }
284};
285#endif
286
287struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
288{
289 .l3proto = PF_INET6,
290 .l4proto = IPPROTO_ICMPV6,
291 .name = "icmpv6",
292 .pkt_to_tuple = icmpv6_pkt_to_tuple,
293 .invert_tuple = icmpv6_invert_tuple,
294 .print_tuple = icmpv6_print_tuple,
295 .packet = icmpv6_packet,
296 .new = icmpv6_new,
297 .error = icmpv6_error,
298#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
299 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
300 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
301 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
302 .nla_policy = icmpv6_nla_policy,
303#endif
304#ifdef CONFIG_SYSCTL
305 .ctl_table_header = &icmpv6_sysctl_header,
306 .ctl_table = icmpv6_sysctl_table,
307#endif
308};
309
