~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c

Version: ~ [ linux-5.14-rc1 ] ~ [ linux-5.13.1 ] ~ [ linux-5.12.16 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.49 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.131 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.197 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.239 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.275 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.275 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Copyright (C)2003,2004 USAGI/WIDE Project
  3  *
  4  * This program is free software; you can redistribute it and/or modify
  5  * it under the terms of the GNU General Public License version 2 as
  6  * published by the Free Software Foundation.
  7  *
  8  * Author:
  9  *      Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 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/ipv6/nf_conntrack_icmpv6.h>
 27 #include <net/netfilter/nf_log.h>
 28 
 29 static unsigned int nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
 30 
 31 static 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 /* Add 1; spaces filled with 0. */
 49 static 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 
 56 static const u_int8_t noct_valid_new[] = {
 57         [ICMPV6_MGM_QUERY - 130] = 1,
 58         [ICMPV6_MGM_REPORT -130] = 1,
 59         [ICMPV6_MGM_REDUCTION - 130] = 1,
 60         [NDISC_ROUTER_SOLICITATION - 130] = 1,
 61         [NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
 62         [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
 63         [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
 64         [ICMPV6_MLD2_REPORT - 130] = 1
 65 };
 66 
 67 static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
 68                                 const struct nf_conntrack_tuple *orig)
 69 {
 70         int type = orig->dst.u.icmp.type - 128;
 71         if (type < 0 || type >= sizeof(invmap) || !invmap[type])
 72                 return false;
 73 
 74         tuple->src.u.icmp.id   = orig->src.u.icmp.id;
 75         tuple->dst.u.icmp.type = invmap[type] - 1;
 76         tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
 77         return true;
 78 }
 79 
 80 /* Print out the per-protocol part of the tuple. */
 81 static int icmpv6_print_tuple(struct seq_file *s,
 82                               const struct nf_conntrack_tuple *tuple)
 83 {
 84         return seq_printf(s, "type=%u code=%u id=%u ",
 85                           tuple->dst.u.icmp.type,
 86                           tuple->dst.u.icmp.code,
 87                           ntohs(tuple->src.u.icmp.id));
 88 }
 89 
 90 /* Returns verdict for packet, or -1 for invalid. */
 91 static int icmpv6_packet(struct nf_conn *ct,
 92                        const struct sk_buff *skb,
 93                        unsigned int dataoff,
 94                        enum ip_conntrack_info ctinfo,
 95                        u_int8_t pf,
 96                        unsigned int hooknum)
 97 {
 98         /* Do not immediately delete the connection after the first
 99            successful reply to avoid excessive conntrackd traffic
100            and also to handle correctly ICMP echo reply duplicates. */
101         nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
102 
103         return NF_ACCEPT;
104 }
105 
106 /* Called when a new connection for this protocol found. */
107 static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
108                        unsigned int dataoff)
109 {
110         static const u_int8_t valid_new[] = {
111                 [ICMPV6_ECHO_REQUEST - 128] = 1,
112                 [ICMPV6_NI_QUERY - 128] = 1
113         };
114         int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
115 
116         if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
117                 /* Can't create a new ICMPv6 `conn' with this. */
118                 pr_debug("icmpv6: can't create new conn with type %u\n",
119                          type + 128);
120                 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
121                 if (LOG_INVALID(nf_ct_net(ct), IPPROTO_ICMPV6))
122                         nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
123                                       "nf_ct_icmpv6: invalid new with type %d ",
124                                       type + 128);
125                 return false;
126         }
127         return true;
128 }
129 
130 static int
131 icmpv6_error_message(struct net *net,
132                      struct sk_buff *skb,
133                      unsigned int icmp6off,
134                      enum ip_conntrack_info *ctinfo,
135                      unsigned int hooknum)
136 {
137         struct nf_conntrack_tuple intuple, origtuple;
138         const struct nf_conntrack_tuple_hash *h;
139         const struct nf_conntrack_l4proto *inproto;
140 
141         NF_CT_ASSERT(skb->nfct == NULL);
142 
143         /* Are they talking about one of our connections? */
144         if (!nf_ct_get_tuplepr(skb,
145                                skb_network_offset(skb)
146                                 + sizeof(struct ipv6hdr)
147                                 + sizeof(struct icmp6hdr),
148                                PF_INET6, &origtuple)) {
149                 pr_debug("icmpv6_error: Can't get tuple\n");
150                 return -NF_ACCEPT;
151         }
152 
153         /* rcu_read_lock()ed by nf_hook_slow */
154         inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
155 
156         /* Ordinarily, we'd expect the inverted tupleproto, but it's
157            been preserved inside the ICMP. */
158         if (!nf_ct_invert_tuple(&intuple, &origtuple,
159                                 &nf_conntrack_l3proto_ipv6, inproto)) {
160                 pr_debug("icmpv6_error: Can't invert tuple\n");
161                 return -NF_ACCEPT;
162         }
163 
164         *ctinfo = IP_CT_RELATED;
165 
166         h = nf_conntrack_find_get(net, &intuple);
167         if (!h) {
168                 pr_debug("icmpv6_error: no match\n");
169                 return -NF_ACCEPT;
170         } else {
171                 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
172                         *ctinfo += IP_CT_IS_REPLY;
173         }
174 
175         /* Update skb to refer to this connection */
176         skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
177         skb->nfctinfo = *ctinfo;
178         return -NF_ACCEPT;
179 }
180 
181 static int
182 icmpv6_error(struct net *net, struct sk_buff *skb, unsigned int dataoff,
183              enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
184 {
185         const struct icmp6hdr *icmp6h;
186         struct icmp6hdr _ih;
187         int type;
188 
189         icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
190         if (icmp6h == NULL) {
191                 if (LOG_INVALID(net, IPPROTO_ICMPV6))
192                 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
193                               "nf_ct_icmpv6: short packet ");
194                 return -NF_ACCEPT;
195         }
196 
197         if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
198             nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
199                 if (LOG_INVALID(net, IPPROTO_ICMPV6))
200                         nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
201                                       "nf_ct_icmpv6: ICMPv6 checksum failed ");
202                 return -NF_ACCEPT;
203         }
204 
205         type = icmp6h->icmp6_type - 130;
206         if (type >= 0 && type < sizeof(noct_valid_new) &&
207             noct_valid_new[type]) {
208                 skb->nfct = &nf_conntrack_untracked.ct_general;
209                 skb->nfctinfo = IP_CT_NEW;
210                 nf_conntrack_get(skb->nfct);
211                 return NF_ACCEPT;
212         }
213 
214         /* is not error message ? */
215         if (icmp6h->icmp6_type >= 128)
216                 return NF_ACCEPT;
217 
218         return icmpv6_error_message(net, skb, dataoff, ctinfo, hooknum);
219 }
220 
221 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
222 
223 #include <linux/netfilter/nfnetlink.h>
224 #include <linux/netfilter/nfnetlink_conntrack.h>
225 static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
226                                   const struct nf_conntrack_tuple *t)
227 {
228         NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
229         NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
230         NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
231 
232         return 0;
233 
234 nla_put_failure:
235         return -1;
236 }
237 
238 static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
239         [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
240         [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
241         [CTA_PROTO_ICMPV6_ID]   = { .type = NLA_U16 },
242 };
243 
244 static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
245                                 struct nf_conntrack_tuple *tuple)
246 {
247         if (!tb[CTA_PROTO_ICMPV6_TYPE]
248             || !tb[CTA_PROTO_ICMPV6_CODE]
249             || !tb[CTA_PROTO_ICMPV6_ID])
250                 return -EINVAL;
251 
252         tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
253         tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
254         tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
255 
256         if (tuple->dst.u.icmp.type < 128
257             || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
258             || !invmap[tuple->dst.u.icmp.type - 128])
259                 return -EINVAL;
260 
261         return 0;
262 }
263 
264 static int icmpv6_nlattr_tuple_size(void)
265 {
266         return nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
267 }
268 #endif
269 
270 #ifdef CONFIG_SYSCTL
271 static struct ctl_table_header *icmpv6_sysctl_header;
272 static struct ctl_table icmpv6_sysctl_table[] = {
273         {
274                 .procname       = "nf_conntrack_icmpv6_timeout",
275                 .data           = &nf_ct_icmpv6_timeout,
276                 .maxlen         = sizeof(unsigned int),
277                 .mode           = 0644,
278                 .proc_handler   = proc_dointvec_jiffies,
279         },
280         {
281                 .ctl_name       = 0
282         }
283 };
284 #endif /* CONFIG_SYSCTL */
285 
286 struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
287 {
288         .l3proto                = PF_INET6,
289         .l4proto                = IPPROTO_ICMPV6,
290         .name                   = "icmpv6",
291         .pkt_to_tuple           = icmpv6_pkt_to_tuple,
292         .invert_tuple           = icmpv6_invert_tuple,
293         .print_tuple            = icmpv6_print_tuple,
294         .packet                 = icmpv6_packet,
295         .new                    = icmpv6_new,
296         .error                  = icmpv6_error,
297 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
298         .tuple_to_nlattr        = icmpv6_tuple_to_nlattr,
299         .nlattr_tuple_size      = icmpv6_nlattr_tuple_size,
300         .nlattr_to_tuple        = icmpv6_nlattr_to_tuple,
301         .nla_policy             = icmpv6_nla_policy,
302 #endif
303 #ifdef CONFIG_SYSCTL
304         .ctl_table_header       = &icmpv6_sysctl_header,
305         .ctl_table              = icmpv6_sysctl_table,
306 #endif
307 };
308 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp