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9#include <linux/types.h>
10#include <linux/timer.h>
11#include <linux/module.h>
12#include <linux/netfilter.h>
13#include <linux/in6.h>
14#include <linux/icmpv6.h>
15#include <linux/ipv6.h>
16#include <net/ipv6.h>
17#include <net/ip6_checksum.h>
18#include <linux/seq_file.h>
19#include <linux/netfilter_ipv6.h>
20#include <net/netfilter/nf_conntrack_tuple.h>
21#include <net/netfilter/nf_conntrack_l4proto.h>
22#include <net/netfilter/nf_conntrack_core.h>
23#include <net/netfilter/nf_conntrack_timeout.h>
24#include <net/netfilter/nf_conntrack_zones.h>
25#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
26#include <net/netfilter/nf_log.h>
27
28static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
29
30bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
31 unsigned int dataoff,
32 struct net *net,
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
67bool nf_conntrack_invert_icmpv6_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
80static unsigned int *icmpv6_get_timeouts(struct net *net)
81{
82 return &nf_icmpv6_pernet(net)->timeout;
83}
84
85
86int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
87 struct sk_buff *skb,
88 enum ip_conntrack_info ctinfo,
89 const struct nf_hook_state *state)
90{
91 unsigned int *timeout = nf_ct_timeout_lookup(ct);
92 static const u8 valid_new[] = {
93 [ICMPV6_ECHO_REQUEST - 128] = 1,
94 [ICMPV6_NI_QUERY - 128] = 1
95 };
96
97 if (state->pf != NFPROTO_IPV6)
98 return -NF_ACCEPT;
99
100 if (!nf_ct_is_confirmed(ct)) {
101 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
102
103 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
104
105 pr_debug("icmpv6: can't create new conn with type %u\n",
106 type + 128);
107 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
108 return -NF_ACCEPT;
109 }
110 }
111
112 if (!timeout)
113 timeout = icmpv6_get_timeouts(nf_ct_net(ct));
114
115
116
117
118 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
119
120 return NF_ACCEPT;
121}
122
123
124static void icmpv6_error_log(const struct sk_buff *skb,
125 const struct nf_hook_state *state,
126 const char *msg)
127{
128 nf_l4proto_log_invalid(skb, state->net, state->pf,
129 IPPROTO_ICMPV6, "%s", msg);
130}
131
132int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
133 struct sk_buff *skb,
134 unsigned int dataoff,
135 const struct nf_hook_state *state)
136{
137 union nf_inet_addr outer_daddr;
138 const struct icmp6hdr *icmp6h;
139 struct icmp6hdr _ih;
140 int type;
141
142 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
143 if (icmp6h == NULL) {
144 icmpv6_error_log(skb, state, "short packet");
145 return -NF_ACCEPT;
146 }
147
148 if (state->hook == NF_INET_PRE_ROUTING &&
149 state->net->ct.sysctl_checksum &&
150 nf_ip6_checksum(skb, state->hook, dataoff, IPPROTO_ICMPV6)) {
151 icmpv6_error_log(skb, state, "ICMPv6 checksum failed");
152 return -NF_ACCEPT;
153 }
154
155 type = icmp6h->icmp6_type - 130;
156 if (type >= 0 && type < sizeof(noct_valid_new) &&
157 noct_valid_new[type]) {
158 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
159 return NF_ACCEPT;
160 }
161
162
163 if (icmp6h->icmp6_type >= 128)
164 return NF_ACCEPT;
165
166 memcpy(&outer_daddr.ip6, &ipv6_hdr(skb)->daddr,
167 sizeof(outer_daddr.ip6));
168 dataoff += sizeof(*icmp6h);
169 return nf_conntrack_inet_error(tmpl, skb, dataoff, state,
170 IPPROTO_ICMPV6, &outer_daddr);
171}
172
173#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
174
175#include <linux/netfilter/nfnetlink.h>
176#include <linux/netfilter/nfnetlink_conntrack.h>
177static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
178 const struct nf_conntrack_tuple *t)
179{
180 if (nla_put_be16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id) ||
181 nla_put_u8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type) ||
182 nla_put_u8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code))
183 goto nla_put_failure;
184 return 0;
185
186nla_put_failure:
187 return -1;
188}
189
190static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
191 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
192 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
193 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
194};
195
196static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
197 struct nf_conntrack_tuple *tuple)
198{
199 if (!tb[CTA_PROTO_ICMPV6_TYPE] ||
200 !tb[CTA_PROTO_ICMPV6_CODE] ||
201 !tb[CTA_PROTO_ICMPV6_ID])
202 return -EINVAL;
203
204 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
205 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
206 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
207
208 if (tuple->dst.u.icmp.type < 128 ||
209 tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
210 !invmap[tuple->dst.u.icmp.type - 128])
211 return -EINVAL;
212
213 return 0;
214}
215
216static unsigned int icmpv6_nlattr_tuple_size(void)
217{
218 static unsigned int size __read_mostly;
219
220 if (!size)
221 size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
222
223 return size;
224}
225#endif
226
227#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
228
229#include <linux/netfilter/nfnetlink.h>
230#include <linux/netfilter/nfnetlink_cttimeout.h>
231
232static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
233 struct net *net, void *data)
234{
235 unsigned int *timeout = data;
236 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
237
238 if (!timeout)
239 timeout = icmpv6_get_timeouts(net);
240 if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
241 *timeout =
242 ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
243 } else {
244
245 *timeout = in->timeout;
246 }
247 return 0;
248}
249
250static int
251icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
252{
253 const unsigned int *timeout = data;
254
255 if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
256 goto nla_put_failure;
257 return 0;
258
259nla_put_failure:
260 return -ENOSPC;
261}
262
263static const struct nla_policy
264icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
265 [CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
266};
267#endif
268
269void nf_conntrack_icmpv6_init_net(struct net *net)
270{
271 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
272
273 in->timeout = nf_ct_icmpv6_timeout;
274}
275
276const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
277{
278 .l4proto = IPPROTO_ICMPV6,
279#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
280 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
281 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
282 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
283 .nla_policy = icmpv6_nla_policy,
284#endif
285#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
286 .ctnl_timeout = {
287 .nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
288 .obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
289 .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
290 .obj_size = sizeof(unsigned int),
291 .nla_policy = icmpv6_timeout_nla_policy,
292 },
293#endif
294};
295
