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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
27#include "nf_internals.h"
28
29static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
30
31bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
32 unsigned int dataoff,
33 struct net *net,
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
68bool nf_conntrack_invert_icmpv6_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
81static unsigned int *icmpv6_get_timeouts(struct net *net)
82{
83 return &nf_icmpv6_pernet(net)->timeout;
84}
85
86
87int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
88 struct sk_buff *skb,
89 enum ip_conntrack_info ctinfo,
90 const struct nf_hook_state *state)
91{
92 unsigned int *timeout = nf_ct_timeout_lookup(ct);
93 static const u8 valid_new[] = {
94 [ICMPV6_ECHO_REQUEST - 128] = 1,
95 [ICMPV6_NI_QUERY - 128] = 1
96 };
97
98 if (state->pf != NFPROTO_IPV6)
99 return -NF_ACCEPT;
100
101 if (!nf_ct_is_confirmed(ct)) {
102 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
103
104 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
105
106 pr_debug("icmpv6: can't create new conn with type %u\n",
107 type + 128);
108 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
109 return -NF_ACCEPT;
110 }
111 }
112
113 if (!timeout)
114 timeout = icmpv6_get_timeouts(nf_ct_net(ct));
115
116
117
118
119 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
120
121 return NF_ACCEPT;
122}
123
124
125static void icmpv6_error_log(const struct sk_buff *skb,
126 const struct nf_hook_state *state,
127 const char *msg)
128{
129 nf_l4proto_log_invalid(skb, state->net, state->pf,
130 IPPROTO_ICMPV6, "%s", msg);
131}
132
133int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
134 struct sk_buff *skb,
135 unsigned int dataoff,
136 const struct nf_hook_state *state)
137{
138 union nf_inet_addr outer_daddr;
139 const struct icmp6hdr *icmp6h;
140 struct icmp6hdr _ih;
141 int type;
142
143 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
144 if (icmp6h == NULL) {
145 icmpv6_error_log(skb, state, "short packet");
146 return -NF_ACCEPT;
147 }
148
149 if (state->hook == NF_INET_PRE_ROUTING &&
150 state->net->ct.sysctl_checksum &&
151 nf_ip6_checksum(skb, state->hook, dataoff, IPPROTO_ICMPV6)) {
152 icmpv6_error_log(skb, state, "ICMPv6 checksum failed");
153 return -NF_ACCEPT;
154 }
155
156 type = icmp6h->icmp6_type - 130;
157 if (type >= 0 && type < sizeof(noct_valid_new) &&
158 noct_valid_new[type]) {
159 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
160 return NF_ACCEPT;
161 }
162
163
164 if (icmp6h->icmp6_type >= 128)
165 return NF_ACCEPT;
166
167 memcpy(&outer_daddr.ip6, &ipv6_hdr(skb)->daddr,
168 sizeof(outer_daddr.ip6));
169 dataoff += sizeof(*icmp6h);
170 return nf_conntrack_inet_error(tmpl, skb, dataoff, state,
171 IPPROTO_ICMPV6, &outer_daddr);
172}
173
174#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
175
176#include <linux/netfilter/nfnetlink.h>
177#include <linux/netfilter/nfnetlink_conntrack.h>
178static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
179 const struct nf_conntrack_tuple *t)
180{
181 if (nla_put_be16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id) ||
182 nla_put_u8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type) ||
183 nla_put_u8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code))
184 goto nla_put_failure;
185 return 0;
186
187nla_put_failure:
188 return -1;
189}
190
191static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
192 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
193 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
194 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
195};
196
197static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
198 struct nf_conntrack_tuple *tuple,
199 u_int32_t flags)
200{
201 if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_TYPE)) {
202 if (!tb[CTA_PROTO_ICMPV6_TYPE])
203 return -EINVAL;
204
205 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
206 if (tuple->dst.u.icmp.type < 128 ||
207 tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
208 !invmap[tuple->dst.u.icmp.type - 128])
209 return -EINVAL;
210 }
211
212 if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_CODE)) {
213 if (!tb[CTA_PROTO_ICMPV6_CODE])
214 return -EINVAL;
215
216 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
217 }
218
219 if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_ID)) {
220 if (!tb[CTA_PROTO_ICMPV6_ID])
221 return -EINVAL;
222
223 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
224 }
225
226 return 0;
227}
228
229static unsigned int icmpv6_nlattr_tuple_size(void)
230{
231 static unsigned int size __read_mostly;
232
233 if (!size)
234 size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
235
236 return size;
237}
238#endif
239
240#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
241
242#include <linux/netfilter/nfnetlink.h>
243#include <linux/netfilter/nfnetlink_cttimeout.h>
244
245static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
246 struct net *net, void *data)
247{
248 unsigned int *timeout = data;
249 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
250
251 if (!timeout)
252 timeout = icmpv6_get_timeouts(net);
253 if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
254 *timeout =
255 ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
256 } else {
257
258 *timeout = in->timeout;
259 }
260 return 0;
261}
262
263static int
264icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
265{
266 const unsigned int *timeout = data;
267
268 if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
269 goto nla_put_failure;
270 return 0;
271
272nla_put_failure:
273 return -ENOSPC;
274}
275
276static const struct nla_policy
277icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
278 [CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
279};
280#endif
281
282void nf_conntrack_icmpv6_init_net(struct net *net)
283{
284 struct nf_icmp_net *in = nf_icmpv6_pernet(net);
285
286 in->timeout = nf_ct_icmpv6_timeout;
287}
288
289const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
290{
291 .l4proto = IPPROTO_ICMPV6,
292#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
293 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
294 .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
295 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
296 .nla_policy = icmpv6_nla_policy,
297#endif
298#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
299 .ctnl_timeout = {
300 .nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
301 .obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
302 .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
303 .obj_size = sizeof(unsigned int),
304 .nla_policy = icmpv6_timeout_nla_policy,
305 },
306#endif
307};
308
