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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/ipv6/nf_conntrack_icmpv6.h>
27#include <net/netfilter/nf_log.h>
28
29static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
30
31static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
32 unsigned int dataoff,
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 bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
57 const struct nf_conntrack_tuple *orig)
58{
59 int type = orig->dst.u.icmp.type - 128;
60 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
61 return false;
62
63 tuple->src.u.icmp.id = orig->src.u.icmp.id;
64 tuple->dst.u.icmp.type = invmap[type] - 1;
65 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
66 return true;
67}
68
69
70static int icmpv6_print_tuple(struct seq_file *s,
71 const struct nf_conntrack_tuple *tuple)
72{
73 return seq_printf(s, "type=%u code=%u id=%u ",
74 tuple->dst.u.icmp.type,
75 tuple->dst.u.icmp.code,
76 ntohs(tuple->src.u.icmp.id));
77}
78
79
80static int icmpv6_packet(struct nf_conn *ct,
81 const struct sk_buff *skb,
82 unsigned int dataoff,
83 enum ip_conntrack_info ctinfo,
84 int pf,
85 unsigned int hooknum)
86{
87
88
89
90
91 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
92 if (atomic_dec_and_test(&ct->proto.icmp.count))
93 nf_ct_kill_acct(ct, ctinfo, skb);
94 } else {
95 atomic_inc(&ct->proto.icmp.count);
96 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
97 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
98 }
99
100 return NF_ACCEPT;
101}
102
103
104static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
105 unsigned int dataoff)
106{
107 static const u_int8_t valid_new[] = {
108 [ICMPV6_ECHO_REQUEST - 128] = 1,
109 [ICMPV6_NI_QUERY - 128] = 1
110 };
111 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
112
113 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
114
115 pr_debug("icmpv6: can't create new conn with type %u\n",
116 type + 128);
117 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
118 return false;
119 }
120 atomic_set(&ct->proto.icmp.count, 0);
121 return true;
122}
123
124static int
125icmpv6_error_message(struct sk_buff *skb,
126 unsigned int icmp6off,
127 enum ip_conntrack_info *ctinfo,
128 unsigned int hooknum)
129{
130 struct nf_conntrack_tuple intuple, origtuple;
131 const struct nf_conntrack_tuple_hash *h;
132 const struct nf_conntrack_l4proto *inproto;
133
134 NF_CT_ASSERT(skb->nfct == NULL);
135
136
137 if (!nf_ct_get_tuplepr(skb,
138 skb_network_offset(skb)
139 + sizeof(struct ipv6hdr)
140 + sizeof(struct icmp6hdr),
141 PF_INET6, &origtuple)) {
142 pr_debug("icmpv6_error: Can't get tuple\n");
143 return -NF_ACCEPT;
144 }
145
146
147 inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
148
149
150
151 if (!nf_ct_invert_tuple(&intuple, &origtuple,
152 &nf_conntrack_l3proto_ipv6, inproto)) {
153 pr_debug("icmpv6_error: Can't invert tuple\n");
154 return -NF_ACCEPT;
155 }
156
157 *ctinfo = IP_CT_RELATED;
158
159 h = nf_conntrack_find_get(&intuple);
160 if (!h) {
161 pr_debug("icmpv6_error: no match\n");
162 return -NF_ACCEPT;
163 } else {
164 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
165 *ctinfo += IP_CT_IS_REPLY;
166 }
167
168
169 skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
170 skb->nfctinfo = *ctinfo;
171 return -NF_ACCEPT;
172}
173
174static int
175icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
176 enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
177{
178 const struct icmp6hdr *icmp6h;
179 struct icmp6hdr _ih;
180
181 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
182 if (icmp6h == NULL) {
183 if (LOG_INVALID(IPPROTO_ICMPV6))
184 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
185 "nf_ct_icmpv6: short packet ");
186 return -NF_ACCEPT;
187 }
188
189 if (nf_conntrack_checksum && hooknum == NF_INET_PRE_ROUTING &&
190 nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
191 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
192 "nf_ct_icmpv6: ICMPv6 checksum failed\n");
193 return -NF_ACCEPT;
194 }
195
196
197 if (icmp6h->icmp6_type >= 128)
198 return NF_ACCEPT;
199
200 return icmpv6_error_message(skb, dataoff, ctinfo, hooknum);
201}
202
203#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
204
205#include <linux/netfilter/nfnetlink.h>
206#include <linux/netfilter/nfnetlink_conntrack.h>
207static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
208 const struct nf_conntrack_tuple *t)
209{
210 NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
211 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
212 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
213
214 return 0;
215
216nla_put_failure:
217 return -1;
218}
219
220static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
221 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
222 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
223 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
224};
225
226static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
227 struct nf_conntrack_tuple *tuple)
228{
229 if (!tb[CTA_PROTO_ICMPV6_TYPE]
230 || !tb[CTA_PROTO_ICMPV6_CODE]
231 || !tb[CTA_PROTO_ICMPV6_ID])
232 return -EINVAL;
233
234 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
235 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
236 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
237
238 if (tuple->dst.u.icmp.type < 128
239 || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
240 || !invmap[tuple->dst.u.icmp.type - 128])
241 return -EINVAL;
242
243 return 0;
244}
245#endif
246
247#ifdef CONFIG_SYSCTL
248static struct ctl_table_header *icmpv6_sysctl_header;
249static struct ctl_table icmpv6_sysctl_table[] = {
250 {
251 .procname = "nf_conntrack_icmpv6_timeout",
252 .data = &nf_ct_icmpv6_timeout,
253 .maxlen = sizeof(unsigned int),
254 .mode = 0644,
255 .proc_handler = &proc_dointvec_jiffies,
256 },
257 {
258 .ctl_name = 0
259 }
260};
261#endif
262
263struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
264{
265 .l3proto = PF_INET6,
266 .l4proto = IPPROTO_ICMPV6,
267 .name = "icmpv6",
268 .pkt_to_tuple = icmpv6_pkt_to_tuple,
269 .invert_tuple = icmpv6_invert_tuple,
270 .print_tuple = icmpv6_print_tuple,
271 .packet = icmpv6_packet,
272 .new = icmpv6_new,
273 .error = icmpv6_error,
274#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
275 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
276 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
277 .nla_policy = icmpv6_nla_policy,
278#endif
279#ifdef CONFIG_SYSCTL
280 .ctl_table_header = &icmpv6_sysctl_header,
281 .ctl_table = icmpv6_sysctl_table,
282#endif
283};
284
