ipv6: sit: better validate user provided tunnel names
[sfrench/cifs-2.6.git] / net / ipv6 / sysctl_net_ipv6.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * sysctl_net_ipv6.c: sysctl interface to net IPV6 subsystem.
4  *
5  * Changes:
6  * YOSHIFUJI Hideaki @USAGI:    added icmp sysctl table.
7  */
8
9 #include <linux/mm.h>
10 #include <linux/sysctl.h>
11 #include <linux/in6.h>
12 #include <linux/ipv6.h>
13 #include <linux/slab.h>
14 #include <linux/export.h>
15 #include <net/ndisc.h>
16 #include <net/ipv6.h>
17 #include <net/addrconf.h>
18 #include <net/inet_frag.h>
19 #include <net/netevent.h>
20 #ifdef CONFIG_NETLABEL
21 #include <net/calipso.h>
22 #endif
23
24 static int zero;
25 static int one = 1;
26 static int auto_flowlabels_min;
27 static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX;
28
29 static int proc_rt6_multipath_hash_policy(struct ctl_table *table, int write,
30                                           void __user *buffer, size_t *lenp,
31                                           loff_t *ppos)
32 {
33         struct net *net;
34         int ret;
35
36         net = container_of(table->data, struct net,
37                            ipv6.sysctl.multipath_hash_policy);
38         ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
39         if (write && ret == 0)
40                 call_netevent_notifiers(NETEVENT_IPV6_MPATH_HASH_UPDATE, net);
41
42         return ret;
43 }
44
45 static struct ctl_table ipv6_table_template[] = {
46         {
47                 .procname       = "bindv6only",
48                 .data           = &init_net.ipv6.sysctl.bindv6only,
49                 .maxlen         = sizeof(int),
50                 .mode           = 0644,
51                 .proc_handler   = proc_dointvec
52         },
53         {
54                 .procname       = "anycast_src_echo_reply",
55                 .data           = &init_net.ipv6.sysctl.anycast_src_echo_reply,
56                 .maxlen         = sizeof(int),
57                 .mode           = 0644,
58                 .proc_handler   = proc_dointvec
59         },
60         {
61                 .procname       = "flowlabel_consistency",
62                 .data           = &init_net.ipv6.sysctl.flowlabel_consistency,
63                 .maxlen         = sizeof(int),
64                 .mode           = 0644,
65                 .proc_handler   = proc_dointvec
66         },
67         {
68                 .procname       = "auto_flowlabels",
69                 .data           = &init_net.ipv6.sysctl.auto_flowlabels,
70                 .maxlen         = sizeof(int),
71                 .mode           = 0644,
72                 .proc_handler   = proc_dointvec_minmax,
73                 .extra1         = &auto_flowlabels_min,
74                 .extra2         = &auto_flowlabels_max
75         },
76         {
77                 .procname       = "fwmark_reflect",
78                 .data           = &init_net.ipv6.sysctl.fwmark_reflect,
79                 .maxlen         = sizeof(int),
80                 .mode           = 0644,
81                 .proc_handler   = proc_dointvec
82         },
83         {
84                 .procname       = "idgen_retries",
85                 .data           = &init_net.ipv6.sysctl.idgen_retries,
86                 .maxlen         = sizeof(int),
87                 .mode           = 0644,
88                 .proc_handler   = proc_dointvec,
89         },
90         {
91                 .procname       = "idgen_delay",
92                 .data           = &init_net.ipv6.sysctl.idgen_delay,
93                 .maxlen         = sizeof(int),
94                 .mode           = 0644,
95                 .proc_handler   = proc_dointvec_jiffies,
96         },
97         {
98                 .procname       = "flowlabel_state_ranges",
99                 .data           = &init_net.ipv6.sysctl.flowlabel_state_ranges,
100                 .maxlen         = sizeof(int),
101                 .mode           = 0644,
102                 .proc_handler   = proc_dointvec
103         },
104         {
105                 .procname       = "ip_nonlocal_bind",
106                 .data           = &init_net.ipv6.sysctl.ip_nonlocal_bind,
107                 .maxlen         = sizeof(int),
108                 .mode           = 0644,
109                 .proc_handler   = proc_dointvec
110         },
111         {
112                 .procname       = "flowlabel_reflect",
113                 .data           = &init_net.ipv6.sysctl.flowlabel_reflect,
114                 .maxlen         = sizeof(int),
115                 .mode           = 0644,
116                 .proc_handler   = proc_dointvec,
117         },
118         {
119                 .procname       = "max_dst_opts_number",
120                 .data           = &init_net.ipv6.sysctl.max_dst_opts_cnt,
121                 .maxlen         = sizeof(int),
122                 .mode           = 0644,
123                 .proc_handler   = proc_dointvec
124         },
125         {
126                 .procname       = "max_hbh_opts_number",
127                 .data           = &init_net.ipv6.sysctl.max_hbh_opts_cnt,
128                 .maxlen         = sizeof(int),
129                 .mode           = 0644,
130                 .proc_handler   = proc_dointvec
131         },
132         {
133                 .procname       = "max_dst_opts_length",
134                 .data           = &init_net.ipv6.sysctl.max_dst_opts_len,
135                 .maxlen         = sizeof(int),
136                 .mode           = 0644,
137                 .proc_handler   = proc_dointvec
138         },
139         {
140                 .procname       = "max_hbh_length",
141                 .data           = &init_net.ipv6.sysctl.max_hbh_opts_len,
142                 .maxlen         = sizeof(int),
143                 .mode           = 0644,
144                 .proc_handler   = proc_dointvec
145         },
146         {
147                 .procname       = "fib_multipath_hash_policy",
148                 .data           = &init_net.ipv6.sysctl.multipath_hash_policy,
149                 .maxlen         = sizeof(int),
150                 .mode           = 0644,
151                 .proc_handler   = proc_rt6_multipath_hash_policy,
152                 .extra1         = &zero,
153                 .extra2         = &one,
154         },
155         { }
156 };
157
158 static struct ctl_table ipv6_rotable[] = {
159         {
160                 .procname       = "mld_max_msf",
161                 .data           = &sysctl_mld_max_msf,
162                 .maxlen         = sizeof(int),
163                 .mode           = 0644,
164                 .proc_handler   = proc_dointvec
165         },
166         {
167                 .procname       = "mld_qrv",
168                 .data           = &sysctl_mld_qrv,
169                 .maxlen         = sizeof(int),
170                 .mode           = 0644,
171                 .proc_handler   = proc_dointvec_minmax,
172                 .extra1         = &one
173         },
174 #ifdef CONFIG_NETLABEL
175         {
176                 .procname       = "calipso_cache_enable",
177                 .data           = &calipso_cache_enabled,
178                 .maxlen         = sizeof(int),
179                 .mode           = 0644,
180                 .proc_handler   = proc_dointvec,
181         },
182         {
183                 .procname       = "calipso_cache_bucket_size",
184                 .data           = &calipso_cache_bucketsize,
185                 .maxlen         = sizeof(int),
186                 .mode           = 0644,
187                 .proc_handler   = proc_dointvec,
188         },
189 #endif /* CONFIG_NETLABEL */
190         { }
191 };
192
193 static int __net_init ipv6_sysctl_net_init(struct net *net)
194 {
195         struct ctl_table *ipv6_table;
196         struct ctl_table *ipv6_route_table;
197         struct ctl_table *ipv6_icmp_table;
198         int err;
199
200         err = -ENOMEM;
201         ipv6_table = kmemdup(ipv6_table_template, sizeof(ipv6_table_template),
202                              GFP_KERNEL);
203         if (!ipv6_table)
204                 goto out;
205         ipv6_table[0].data = &net->ipv6.sysctl.bindv6only;
206         ipv6_table[1].data = &net->ipv6.sysctl.anycast_src_echo_reply;
207         ipv6_table[2].data = &net->ipv6.sysctl.flowlabel_consistency;
208         ipv6_table[3].data = &net->ipv6.sysctl.auto_flowlabels;
209         ipv6_table[4].data = &net->ipv6.sysctl.fwmark_reflect;
210         ipv6_table[5].data = &net->ipv6.sysctl.idgen_retries;
211         ipv6_table[6].data = &net->ipv6.sysctl.idgen_delay;
212         ipv6_table[7].data = &net->ipv6.sysctl.flowlabel_state_ranges;
213         ipv6_table[8].data = &net->ipv6.sysctl.ip_nonlocal_bind;
214         ipv6_table[9].data = &net->ipv6.sysctl.flowlabel_reflect;
215         ipv6_table[10].data = &net->ipv6.sysctl.max_dst_opts_cnt;
216         ipv6_table[11].data = &net->ipv6.sysctl.max_hbh_opts_cnt;
217         ipv6_table[12].data = &net->ipv6.sysctl.max_dst_opts_len;
218         ipv6_table[13].data = &net->ipv6.sysctl.max_hbh_opts_len;
219         ipv6_table[14].data = &net->ipv6.sysctl.multipath_hash_policy,
220
221         ipv6_route_table = ipv6_route_sysctl_init(net);
222         if (!ipv6_route_table)
223                 goto out_ipv6_table;
224
225         ipv6_icmp_table = ipv6_icmp_sysctl_init(net);
226         if (!ipv6_icmp_table)
227                 goto out_ipv6_route_table;
228
229         net->ipv6.sysctl.hdr = register_net_sysctl(net, "net/ipv6", ipv6_table);
230         if (!net->ipv6.sysctl.hdr)
231                 goto out_ipv6_icmp_table;
232
233         net->ipv6.sysctl.route_hdr =
234                 register_net_sysctl(net, "net/ipv6/route", ipv6_route_table);
235         if (!net->ipv6.sysctl.route_hdr)
236                 goto out_unregister_ipv6_table;
237
238         net->ipv6.sysctl.icmp_hdr =
239                 register_net_sysctl(net, "net/ipv6/icmp", ipv6_icmp_table);
240         if (!net->ipv6.sysctl.icmp_hdr)
241                 goto out_unregister_route_table;
242
243         err = 0;
244 out:
245         return err;
246 out_unregister_route_table:
247         unregister_net_sysctl_table(net->ipv6.sysctl.route_hdr);
248 out_unregister_ipv6_table:
249         unregister_net_sysctl_table(net->ipv6.sysctl.hdr);
250 out_ipv6_icmp_table:
251         kfree(ipv6_icmp_table);
252 out_ipv6_route_table:
253         kfree(ipv6_route_table);
254 out_ipv6_table:
255         kfree(ipv6_table);
256         goto out;
257 }
258
259 static void __net_exit ipv6_sysctl_net_exit(struct net *net)
260 {
261         struct ctl_table *ipv6_table;
262         struct ctl_table *ipv6_route_table;
263         struct ctl_table *ipv6_icmp_table;
264
265         ipv6_table = net->ipv6.sysctl.hdr->ctl_table_arg;
266         ipv6_route_table = net->ipv6.sysctl.route_hdr->ctl_table_arg;
267         ipv6_icmp_table = net->ipv6.sysctl.icmp_hdr->ctl_table_arg;
268
269         unregister_net_sysctl_table(net->ipv6.sysctl.icmp_hdr);
270         unregister_net_sysctl_table(net->ipv6.sysctl.route_hdr);
271         unregister_net_sysctl_table(net->ipv6.sysctl.hdr);
272
273         kfree(ipv6_table);
274         kfree(ipv6_route_table);
275         kfree(ipv6_icmp_table);
276 }
277
278 static struct pernet_operations ipv6_sysctl_net_ops = {
279         .init = ipv6_sysctl_net_init,
280         .exit = ipv6_sysctl_net_exit,
281 };
282
283 static struct ctl_table_header *ip6_header;
284
285 int ipv6_sysctl_register(void)
286 {
287         int err = -ENOMEM;
288
289         ip6_header = register_net_sysctl(&init_net, "net/ipv6", ipv6_rotable);
290         if (!ip6_header)
291                 goto out;
292
293         err = register_pernet_subsys(&ipv6_sysctl_net_ops);
294         if (err)
295                 goto err_pernet;
296 out:
297         return err;
298
299 err_pernet:
300         unregister_net_sysctl_table(ip6_header);
301         goto out;
302 }
303
304 void ipv6_sysctl_unregister(void)
305 {
306         unregister_net_sysctl_table(ip6_header);
307         unregister_pernet_subsys(&ipv6_sysctl_net_ops);
308 }