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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/nf_log.h>
26
27static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
28
29bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
30 unsigned int dataoff,
31 struct net *net,
32 struct nf_conntrack_tuple *tuple)
33{
34 const struct icmp6hdr *hp;
35 struct icmp6hdr _hdr;
36
37 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
38 if (hp == NULL)
39 return false;
40 tuple->dst.u.icmp.type = hp->icmp6_type;
41 tuple->src.u.icmp.id = hp->icmp6_identifier;
42 tuple->dst.u.icmp.code = hp->icmp6_code;
43
44 return true;
45}
46
47
48static const u_int8_t invmap[] = {
49 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
50 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
51 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1,
52 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY + 1
53};
54
55static const u_int8_t noct_valid_new[] = {
56 [ICMPV6_MGM_QUERY - 130] = 1,
57 [ICMPV6_MGM_REPORT - 130] = 1,
58 [ICMPV6_MGM_REDUCTION - 130] = 1,
59 [NDISC_ROUTER_SOLICITATION - 130] = 1,
60 [NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
61 [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
62 [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
63 [ICMPV6_MLD2_REPORT - 130] = 1
64};
65
66bool nf_conntrack_invert_icmpv6_tuple(struct nf_conntrack_tuple *tuple,
67 const struct nf_conntrack_tuple *orig)
68{
69 int type = orig->dst.u.icmp.type - 128;
70 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
71 return false;
72
73 tuple->src.u.icmp.id = orig->src.u.icmp.id;
74 tuple->dst.u.icmp.type = invmap[type] - 1;
75 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
76 return true;
77}
78
79static unsigned int *icmpv6_get_timeouts(struct net *net)
80{
81 return &nf_icmpv6_pernet(net)->timeout;
82}
83
84
85int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
86 struct sk_buff *skb,
87 enum ip_conntrack_info ctinfo,
88 const struct nf_hook_state *state)
89{
90 unsigned int *timeout = nf_ct_timeout_lookup(ct);
91 static const u8 valid_new[] = {
92 [ICMPV6_ECHO_REQUEST - 128] = 1,
93 [ICMPV6_NI_QUERY - 128] = 1
94 };
95
96 if (state->pf != NFPROTO_IPV6)
97 return -NF_ACCEPT;
98
99 if (!nf_ct_is_confirmed(ct)) {
100 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
101
102 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
103
104 pr_debug("icmpv6: can't create new conn with type %u\n",
105 type + 128);
106 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
107 return -NF_ACCEPT;
108 }
109 }
110
111 if (!timeout)
112 timeout = icmpv6_get_timeouts(nf_ct_net(ct));
113
114
115
116
117 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
118
119 return NF_ACCEPT;
120}
121
122
123static void icmpv6_error_log(const struct sk_buff *skb,
124 const struct nf_hook_state *state,
125 const char *msg)
126{
127 nf_l4proto_log_invalid(skb, state->net, state->pf,
128 IPPROTO_ICMPV6, "%s", msg);
129}
130
131int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
132 struct sk_buff *skb,
133 unsigned int dataoff,
134 const struct nf_hook_state *state)
135{
136 union nf_inet_addr outer_daddr;
137 const struct icmp6hdr *icmp6h;
138 struct icmp6hdr _ih;
139 int type;
140
141 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
142 if (icmp6h == NULL) {
143 icmpv6_error_log(skb, state, "short packet");
144 return -NF_ACCEPT;
145 }
146
147 if (state->hook == NF_INET_PRE_ROUTING &&
148 state->net->ct.sysctl_checksum &&
149 nf_ip6_checksum(skb, state->hook, dataoff, IPPROTO_ICMPV6)) {
150 icmpv6_error_log(skb, state, "ICMPv6 checksum failed");
151 return -NF_ACCEPT;
152 }
153
154 type = icmp6h->icmp6_type - 130;
155 if (type >= 0 && type < sizeof(noct_valid_new) &&
156 noct_valid_new[type]) {
157 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
158 return NF_ACCEPT;
159 }
160
161
162 if (icmp6h->icmp6_type >= 128)
163 return NF_ACCEPT;
164
165 memcpy(&outer_daddr.ip6, &ipv6_hdr(skb)->daddr,
166 sizeof(outer_daddr.ip6));
167 dataoff += sizeof(*icmp6h);
168 return nf_conntrack_inet_error(tmpl, skb, dataoff, state,
169 IPPROTO_ICMPV6, &outer_daddr);
170}
171
172#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
173
174#include <linux/netfilter/nfnetlink.h>
175#include <linux/netfilter/nfnetlink_conntrack.h>
176static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
177 const struct nf_conntrack_tuple *t)
178{
179 if (nla_put_be16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id) ||
180 nla_put_u8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type) ||
181 nla_put_u8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code))
182 goto nla_put_failure;
183 return 0;
184
185nla_put_failure:
186 return -1;
187}
188
189static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
190 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
191 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
192 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
193};
194
195static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
196 struct nf_conntrack_tuple *tuple)
197{
198 if (!tb[CTA_PROTO_ICMPV6_TYPE] ||
199 !tb[CTA_PROTO_ICMPV6_CODE] ||
200 !tb[CTA_PROTO_ICMPV6_ID])
201 return -EINVAL;
202
203 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
204 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
205 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
206
207 if (tuple->dst.u.icmp.type < 128 ||
208 tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
209 !invmap[tuple->dst.u.icmp.type - 128])
210 return -EINVAL;
211
212 return 0;
213}
214
215static unsigned int icmpv6_nlattr_tuple_size(void)
216{
217 static unsigned int size __read_mostly;
218
219 if (!size)
220 size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
221
222 return size;
223}
224#endif
225
226#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
227
228#include <linux/netfilter/nfnetlink.h>
229#include <linux/netfilter/nfnetlink_cttimeout.h>
230
231static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
232 struct net *net, void *data)
233{
234 unsigned int *timeout = data;
235 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
236
237 if (!timeout)
238 timeout = icmpv6_get_timeouts(net);
239 if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
240 *timeout =
241 ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
242 } else {
243
244 *timeout = in->timeout;
245 }
246 return 0;
247}
248
249static int
250icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
251{
252 const unsigned int *timeout = data;
253
254 if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
255 goto nla_put_failure;
256 return 0;
257
258nla_put_failure:
259 return -ENOSPC;
260}
261
262static const struct nla_policy
263icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
264 [CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
265};
266#endif
267
268void nf_conntrack_icmpv6_init_net(struct net *net)
269{
270 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
271
272 in->timeout = nf_ct_icmpv6_timeout;
273}
274
275const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
276{
277 .l4proto = IPPROTO_ICMPV6,
278#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
279 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
280 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
281 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
282 .nla_policy = icmpv6_nla_policy,
283#endif
284#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
285 .ctnl_timeout = {
286 .nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
287 .obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
288 .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
289 .obj_size = sizeof(unsigned int),
290 .nla_policy = icmpv6_timeout_nla_policy,
291 },
292#endif
293};
294
