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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_timeout.h>
27#include <net/netfilter/nf_conntrack_zones.h>
28#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
29#include <net/netfilter/nf_log.h>
30
31#include "nf_internals.h"
32
33static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
34
35bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
36 unsigned int dataoff,
37 struct net *net,
38 struct nf_conntrack_tuple *tuple)
39{
40 const struct icmp6hdr *hp;
41 struct icmp6hdr _hdr;
42
43 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
44 if (hp == NULL)
45 return false;
46 tuple->dst.u.icmp.type = hp->icmp6_type;
47 tuple->src.u.icmp.id = hp->icmp6_identifier;
48 tuple->dst.u.icmp.code = hp->icmp6_code;
49
50 return true;
51}
52
53
54static const u_int8_t invmap[] = {
55 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
56 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
57 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1,
58 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY + 1
59};
60
61static const u_int8_t noct_valid_new[] = {
62 [ICMPV6_MGM_QUERY - 130] = 1,
63 [ICMPV6_MGM_REPORT - 130] = 1,
64 [ICMPV6_MGM_REDUCTION - 130] = 1,
65 [NDISC_ROUTER_SOLICITATION - 130] = 1,
66 [NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
67 [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
68 [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
69 [ICMPV6_MLD2_REPORT - 130] = 1
70};
71
72bool nf_conntrack_invert_icmpv6_tuple(struct nf_conntrack_tuple *tuple,
73 const struct nf_conntrack_tuple *orig)
74{
75 int type = orig->dst.u.icmp.type - 128;
76 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
77 return false;
78
79 tuple->src.u.icmp.id = orig->src.u.icmp.id;
80 tuple->dst.u.icmp.type = invmap[type] - 1;
81 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
82 return true;
83}
84
85static unsigned int *icmpv6_get_timeouts(struct net *net)
86{
87 return &nf_icmpv6_pernet(net)->timeout;
88}
89
90
91int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
92 struct sk_buff *skb,
93 enum ip_conntrack_info ctinfo,
94 const struct nf_hook_state *state)
95{
96 unsigned int *timeout = nf_ct_timeout_lookup(ct);
97 static const u8 valid_new[] = {
98 [ICMPV6_ECHO_REQUEST - 128] = 1,
99 [ICMPV6_NI_QUERY - 128] = 1
100 };
101
102 if (state->pf != NFPROTO_IPV6)
103 return -NF_ACCEPT;
104
105 if (!nf_ct_is_confirmed(ct)) {
106 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
107
108 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
109
110 pr_debug("icmpv6: can't create new conn with type %u\n",
111 type + 128);
112 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
113 return -NF_ACCEPT;
114 }
115 }
116
117 if (!timeout)
118 timeout = icmpv6_get_timeouts(nf_ct_net(ct));
119
120
121
122
123 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
124
125 return NF_ACCEPT;
126}
127
128
129static void icmpv6_error_log(const struct sk_buff *skb,
130 const struct nf_hook_state *state,
131 const char *msg)
132{
133 nf_l4proto_log_invalid(skb, state->net, state->pf,
134 IPPROTO_ICMPV6, "%s", msg);
135}
136
137int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
138 struct sk_buff *skb,
139 unsigned int dataoff,
140 const struct nf_hook_state *state)
141{
142 union nf_inet_addr outer_daddr;
143 const struct icmp6hdr *icmp6h;
144 struct icmp6hdr _ih;
145 int type;
146
147 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
148 if (icmp6h == NULL) {
149 icmpv6_error_log(skb, state, "short packet");
150 return -NF_ACCEPT;
151 }
152
153 if (state->hook == NF_INET_PRE_ROUTING &&
154 state->net->ct.sysctl_checksum &&
155 nf_ip6_checksum(skb, state->hook, dataoff, IPPROTO_ICMPV6)) {
156 icmpv6_error_log(skb, state, "ICMPv6 checksum failed");
157 return -NF_ACCEPT;
158 }
159
160 type = icmp6h->icmp6_type - 130;
161 if (type >= 0 && type < sizeof(noct_valid_new) &&
162 noct_valid_new[type]) {
163 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
164 return NF_ACCEPT;
165 }
166
167
168 if (icmp6h->icmp6_type >= 128)
169 return NF_ACCEPT;
170
171 memcpy(&outer_daddr.ip6, &ipv6_hdr(skb)->daddr,
172 sizeof(outer_daddr.ip6));
173 dataoff += sizeof(*icmp6h);
174 return nf_conntrack_inet_error(tmpl, skb, dataoff, state,
175 IPPROTO_ICMPV6, &outer_daddr);
176}
177
178#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
179
180#include <linux/netfilter/nfnetlink.h>
181#include <linux/netfilter/nfnetlink_conntrack.h>
182static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
183 const struct nf_conntrack_tuple *t)
184{
185 if (nla_put_be16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id) ||
186 nla_put_u8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type) ||
187 nla_put_u8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code))
188 goto nla_put_failure;
189 return 0;
190
191nla_put_failure:
192 return -1;
193}
194
195static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
196 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
197 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
198 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
199};
200
201static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
202 struct nf_conntrack_tuple *tuple,
203 u_int32_t flags)
204{
205 if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_TYPE)) {
206 if (!tb[CTA_PROTO_ICMPV6_TYPE])
207 return -EINVAL;
208
209 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
210 if (tuple->dst.u.icmp.type < 128 ||
211 tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
212 !invmap[tuple->dst.u.icmp.type - 128])
213 return -EINVAL;
214 }
215
216 if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_CODE)) {
217 if (!tb[CTA_PROTO_ICMPV6_CODE])
218 return -EINVAL;
219
220 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
221 }
222
223 if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_ID)) {
224 if (!tb[CTA_PROTO_ICMPV6_ID])
225 return -EINVAL;
226
227 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
228 }
229
230 return 0;
231}
232
233static unsigned int icmpv6_nlattr_tuple_size(void)
234{
235 static unsigned int size __read_mostly;
236
237 if (!size)
238 size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
239
240 return size;
241}
242#endif
243
244#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
245
246#include <linux/netfilter/nfnetlink.h>
247#include <linux/netfilter/nfnetlink_cttimeout.h>
248
249static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
250 struct net *net, void *data)
251{
252 unsigned int *timeout = data;
253 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
254
255 if (!timeout)
256 timeout = icmpv6_get_timeouts(net);
257 if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
258 *timeout =
259 ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
260 } else {
261
262 *timeout = in->timeout;
263 }
264 return 0;
265}
266
267static int
268icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
269{
270 const unsigned int *timeout = data;
271
272 if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
273 goto nla_put_failure;
274 return 0;
275
276nla_put_failure:
277 return -ENOSPC;
278}
279
280static const struct nla_policy
281icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
282 [CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
283};
284#endif
285
286#ifdef CONFIG_SYSCTL
287static struct ctl_table icmpv6_sysctl_table[] = {
288 {
289 .procname = "nf_conntrack_icmpv6_timeout",
290 .maxlen = sizeof(unsigned int),
291 .mode = 0644,
292 .proc_handler = proc_dointvec_jiffies,
293 },
294 { }
295};
296#endif
297
298static int icmpv6_kmemdup_sysctl_table(struct nf_proto_net *pn,
299 struct nf_icmp_net *in)
300{
301#ifdef CONFIG_SYSCTL
302 pn->ctl_table = kmemdup(icmpv6_sysctl_table,
303 sizeof(icmpv6_sysctl_table),
304 GFP_KERNEL);
305 if (!pn->ctl_table)
306 return -ENOMEM;
307
308 pn->ctl_table[0].data = &in->timeout;
309#endif
310 return 0;
311}
312
313static int icmpv6_init_net(struct net *net)
314{
315 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
316 struct nf_proto_net *pn = &in->pn;
317
318 in->timeout = nf_ct_icmpv6_timeout;
319
320 return icmpv6_kmemdup_sysctl_table(pn, in);
321}
322
323static struct nf_proto_net *icmpv6_get_net_proto(struct net *net)
324{
325 return &net->ct.nf_ct_proto.icmpv6.pn;
326}
327
328const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
329{
330 .l4proto = IPPROTO_ICMPV6,
331#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
332 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
333 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
334 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
335 .nla_policy = icmpv6_nla_policy,
336#endif
337#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
338 .ctnl_timeout = {
339 .nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
340 .obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
341 .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
342 .obj_size = sizeof(unsigned int),
343 .nla_policy = icmpv6_timeout_nla_policy,
344 },
345#endif
346 .init_net = icmpv6_init_net,
347 .get_net_proto = icmpv6_get_net_proto,
348};
349
