1
2
3
4
5
6
7
8
9
10
11
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
31static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
32
33bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
34 unsigned int dataoff,
35 struct net *net,
36 struct nf_conntrack_tuple *tuple)
37{
38 const struct icmp6hdr *hp;
39 struct icmp6hdr _hdr;
40
41 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
42 if (hp == NULL)
43 return false;
44 tuple->dst.u.icmp.type = hp->icmp6_type;
45 tuple->src.u.icmp.id = hp->icmp6_identifier;
46 tuple->dst.u.icmp.code = hp->icmp6_code;
47
48 return true;
49}
50
51
52static const u_int8_t invmap[] = {
53 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
54 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
55 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1,
56 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY + 1
57};
58
59static const u_int8_t noct_valid_new[] = {
60 [ICMPV6_MGM_QUERY - 130] = 1,
61 [ICMPV6_MGM_REPORT - 130] = 1,
62 [ICMPV6_MGM_REDUCTION - 130] = 1,
63 [NDISC_ROUTER_SOLICITATION - 130] = 1,
64 [NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
65 [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
66 [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
67 [ICMPV6_MLD2_REPORT - 130] = 1
68};
69
70bool nf_conntrack_invert_icmpv6_tuple(struct nf_conntrack_tuple *tuple,
71 const struct nf_conntrack_tuple *orig)
72{
73 int type = orig->dst.u.icmp.type - 128;
74 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
75 return false;
76
77 tuple->src.u.icmp.id = orig->src.u.icmp.id;
78 tuple->dst.u.icmp.type = invmap[type] - 1;
79 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
80 return true;
81}
82
83static unsigned int *icmpv6_get_timeouts(struct net *net)
84{
85 return &nf_icmpv6_pernet(net)->timeout;
86}
87
88
89int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
90 struct sk_buff *skb,
91 enum ip_conntrack_info ctinfo,
92 const struct nf_hook_state *state)
93{
94 unsigned int *timeout = nf_ct_timeout_lookup(ct);
95 static const u8 valid_new[] = {
96 [ICMPV6_ECHO_REQUEST - 128] = 1,
97 [ICMPV6_NI_QUERY - 128] = 1
98 };
99
100 if (state->pf != NFPROTO_IPV6)
101 return -NF_ACCEPT;
102
103 if (!nf_ct_is_confirmed(ct)) {
104 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
105
106 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
107
108 pr_debug("icmpv6: can't create new conn with type %u\n",
109 type + 128);
110 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
111 return -NF_ACCEPT;
112 }
113 }
114
115 if (!timeout)
116 timeout = icmpv6_get_timeouts(nf_ct_net(ct));
117
118
119
120
121 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
122
123 return NF_ACCEPT;
124}
125
126
127static void icmpv6_error_log(const struct sk_buff *skb,
128 const struct nf_hook_state *state,
129 const char *msg)
130{
131 nf_l4proto_log_invalid(skb, state->net, state->pf,
132 IPPROTO_ICMPV6, "%s", msg);
133}
134
135int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
136 struct sk_buff *skb,
137 unsigned int dataoff,
138 const struct nf_hook_state *state)
139{
140 union nf_inet_addr outer_daddr;
141 const struct icmp6hdr *icmp6h;
142 struct icmp6hdr _ih;
143 int type;
144
145 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
146 if (icmp6h == NULL) {
147 icmpv6_error_log(skb, state, "short packet");
148 return -NF_ACCEPT;
149 }
150
151 if (state->hook == NF_INET_PRE_ROUTING &&
152 state->net->ct.sysctl_checksum &&
153 nf_ip6_checksum(skb, state->hook, dataoff, IPPROTO_ICMPV6)) {
154 icmpv6_error_log(skb, state, "ICMPv6 checksum failed");
155 return -NF_ACCEPT;
156 }
157
158 type = icmp6h->icmp6_type - 130;
159 if (type >= 0 && type < sizeof(noct_valid_new) &&
160 noct_valid_new[type]) {
161 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
162 return NF_ACCEPT;
163 }
164
165
166 if (icmp6h->icmp6_type >= 128)
167 return NF_ACCEPT;
168
169 memcpy(&outer_daddr.ip6, &ipv6_hdr(skb)->daddr,
170 sizeof(outer_daddr.ip6));
171 dataoff += sizeof(*icmp6h);
172 return nf_conntrack_inet_error(tmpl, skb, dataoff, state,
173 IPPROTO_ICMPV6, &outer_daddr);
174}
175
176#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
177
178#include <linux/netfilter/nfnetlink.h>
179#include <linux/netfilter/nfnetlink_conntrack.h>
180static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
181 const struct nf_conntrack_tuple *t)
182{
183 if (nla_put_be16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id) ||
184 nla_put_u8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type) ||
185 nla_put_u8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code))
186 goto nla_put_failure;
187 return 0;
188
189nla_put_failure:
190 return -1;
191}
192
193static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
194 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
195 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
196 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
197};
198
199static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
200 struct nf_conntrack_tuple *tuple)
201{
202 if (!tb[CTA_PROTO_ICMPV6_TYPE] ||
203 !tb[CTA_PROTO_ICMPV6_CODE] ||
204 !tb[CTA_PROTO_ICMPV6_ID])
205 return -EINVAL;
206
207 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
208 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
209 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
210
211 if (tuple->dst.u.icmp.type < 128 ||
212 tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
213 !invmap[tuple->dst.u.icmp.type - 128])
214 return -EINVAL;
215
216 return 0;
217}
218
219static unsigned int icmpv6_nlattr_tuple_size(void)
220{
221 static unsigned int size __read_mostly;
222
223 if (!size)
224 size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
225
226 return size;
227}
228#endif
229
230#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
231
232#include <linux/netfilter/nfnetlink.h>
233#include <linux/netfilter/nfnetlink_cttimeout.h>
234
235static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
236 struct net *net, void *data)
237{
238 unsigned int *timeout = data;
239 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
240
241 if (!timeout)
242 timeout = icmpv6_get_timeouts(net);
243 if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
244 *timeout =
245 ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
246 } else {
247
248 *timeout = in->timeout;
249 }
250 return 0;
251}
252
253static int
254icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
255{
256 const unsigned int *timeout = data;
257
258 if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
259 goto nla_put_failure;
260 return 0;
261
262nla_put_failure:
263 return -ENOSPC;
264}
265
266static const struct nla_policy
267icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
268 [CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
269};
270#endif
271
272#ifdef CONFIG_SYSCTL
273static struct ctl_table icmpv6_sysctl_table[] = {
274 {
275 .procname = "nf_conntrack_icmpv6_timeout",
276 .maxlen = sizeof(unsigned int),
277 .mode = 0644,
278 .proc_handler = proc_dointvec_jiffies,
279 },
280 { }
281};
282#endif
283
284static int icmpv6_kmemdup_sysctl_table(struct nf_proto_net *pn,
285 struct nf_icmp_net *in)
286{
287#ifdef CONFIG_SYSCTL
288 pn->ctl_table = kmemdup(icmpv6_sysctl_table,
289 sizeof(icmpv6_sysctl_table),
290 GFP_KERNEL);
291 if (!pn->ctl_table)
292 return -ENOMEM;
293
294 pn->ctl_table[0].data = &in->timeout;
295#endif
296 return 0;
297}
298
299static int icmpv6_init_net(struct net *net)
300{
301 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
302 struct nf_proto_net *pn = &in->pn;
303
304 in->timeout = nf_ct_icmpv6_timeout;
305
306 return icmpv6_kmemdup_sysctl_table(pn, in);
307}
308
309static struct nf_proto_net *icmpv6_get_net_proto(struct net *net)
310{
311 return &net->ct.nf_ct_proto.icmpv6.pn;
312}
313
314const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
315{
316 .l4proto = IPPROTO_ICMPV6,
317#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
318 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
319 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
320 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
321 .nla_policy = icmpv6_nla_policy,
322#endif
323#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
324 .ctnl_timeout = {
325 .nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
326 .obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
327 .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
328 .obj_size = sizeof(unsigned int),
329 .nla_policy = icmpv6_timeout_nla_policy,
330 },
331#endif
332 .init_net = icmpv6_init_net,
333 .get_net_proto = icmpv6_get_net_proto,
334};
335
