netfilter: ipv6: fix crash caused by ipv6_find_hdr()
[linux-2.6.git] / net / ipv6 / netfilter / ip6_tables.c
1 /*
2  * Packet matching code.
3  *
4  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5  * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/capability.h>
13 #include <linux/in.h>
14 #include <linux/skbuff.h>
15 #include <linux/kmod.h>
16 #include <linux/vmalloc.h>
17 #include <linux/netdevice.h>
18 #include <linux/module.h>
19 #include <linux/poison.h>
20 #include <linux/icmpv6.h>
21 #include <net/ipv6.h>
22 #include <net/compat.h>
23 #include <asm/uaccess.h>
24 #include <linux/mutex.h>
25 #include <linux/proc_fs.h>
26 #include <linux/err.h>
27 #include <linux/cpumask.h>
28
29 #include <linux/netfilter_ipv6/ip6_tables.h>
30 #include <linux/netfilter/x_tables.h>
31 #include <net/netfilter/nf_log.h>
32 #include "../../netfilter/xt_repldata.h"
33
34 MODULE_LICENSE("GPL");
35 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
36 MODULE_DESCRIPTION("IPv6 packet filter");
37
38 /*#define DEBUG_IP_FIREWALL*/
39 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
40 /*#define DEBUG_IP_FIREWALL_USER*/
41
42 #ifdef DEBUG_IP_FIREWALL
43 #define dprintf(format, args...) pr_info(format , ## args)
44 #else
45 #define dprintf(format, args...)
46 #endif
47
48 #ifdef DEBUG_IP_FIREWALL_USER
49 #define duprintf(format, args...) pr_info(format , ## args)
50 #else
51 #define duprintf(format, args...)
52 #endif
53
54 #ifdef CONFIG_NETFILTER_DEBUG
55 #define IP_NF_ASSERT(x) WARN_ON(!(x))
56 #else
57 #define IP_NF_ASSERT(x)
58 #endif
59
60 #if 0
61 /* All the better to debug you with... */
62 #define static
63 #define inline
64 #endif
65
66 void *ip6t_alloc_initial_table(const struct xt_table *info)
67 {
68         return xt_alloc_initial_table(ip6t, IP6T);
69 }
70 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);
71
72 /*
73    We keep a set of rules for each CPU, so we can avoid write-locking
74    them in the softirq when updating the counters and therefore
75    only need to read-lock in the softirq; doing a write_lock_bh() in user
76    context stops packets coming through and allows user context to read
77    the counters or update the rules.
78
79    Hence the start of any table is given by get_table() below.  */
80
81 /* Check for an extension */
82 int
83 ip6t_ext_hdr(u8 nexthdr)
84 {
85         return  (nexthdr == IPPROTO_HOPOPTS)   ||
86                 (nexthdr == IPPROTO_ROUTING)   ||
87                 (nexthdr == IPPROTO_FRAGMENT)  ||
88                 (nexthdr == IPPROTO_ESP)       ||
89                 (nexthdr == IPPROTO_AH)        ||
90                 (nexthdr == IPPROTO_NONE)      ||
91                 (nexthdr == IPPROTO_DSTOPTS);
92 }
93
94 /* Returns whether matches rule or not. */
95 /* Performance critical - called for every packet */
96 static inline bool
97 ip6_packet_match(const struct sk_buff *skb,
98                  const char *indev,
99                  const char *outdev,
100                  const struct ip6t_ip6 *ip6info,
101                  unsigned int *protoff,
102                  int *fragoff, bool *hotdrop)
103 {
104         unsigned long ret;
105         const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
106
107 #define FWINV(bool, invflg) ((bool) ^ !!(ip6info->invflags & (invflg)))
108
109         if (FWINV(ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
110                                        &ip6info->src), IP6T_INV_SRCIP) ||
111             FWINV(ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
112                                        &ip6info->dst), IP6T_INV_DSTIP)) {
113                 dprintf("Source or dest mismatch.\n");
114 /*
115                 dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr,
116                         ipinfo->smsk.s_addr, ipinfo->src.s_addr,
117                         ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : "");
118                 dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr,
119                         ipinfo->dmsk.s_addr, ipinfo->dst.s_addr,
120                         ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/
121                 return false;
122         }
123
124         ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);
125
126         if (FWINV(ret != 0, IP6T_INV_VIA_IN)) {
127                 dprintf("VIA in mismatch (%s vs %s).%s\n",
128                         indev, ip6info->iniface,
129                         ip6info->invflags&IP6T_INV_VIA_IN ?" (INV)":"");
130                 return false;
131         }
132
133         ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);
134
135         if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) {
136                 dprintf("VIA out mismatch (%s vs %s).%s\n",
137                         outdev, ip6info->outiface,
138                         ip6info->invflags&IP6T_INV_VIA_OUT ?" (INV)":"");
139                 return false;
140         }
141
142 /* ... might want to do something with class and flowlabel here ... */
143
144         /* look for the desired protocol header */
145         if((ip6info->flags & IP6T_F_PROTO)) {
146                 int protohdr;
147                 unsigned short _frag_off;
148
149                 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off);
150                 if (protohdr < 0) {
151                         if (_frag_off == 0)
152                                 *hotdrop = true;
153                         return false;
154                 }
155                 *fragoff = _frag_off;
156
157                 dprintf("Packet protocol %hi ?= %s%hi.\n",
158                                 protohdr,
159                                 ip6info->invflags & IP6T_INV_PROTO ? "!":"",
160                                 ip6info->proto);
161
162                 if (ip6info->proto == protohdr) {
163                         if(ip6info->invflags & IP6T_INV_PROTO) {
164                                 return false;
165                         }
166                         return true;
167                 }
168
169                 /* We need match for the '-p all', too! */
170                 if ((ip6info->proto != 0) &&
171                         !(ip6info->invflags & IP6T_INV_PROTO))
172                         return false;
173         }
174         return true;
175 }
176
177 /* should be ip6 safe */
178 static bool
179 ip6_checkentry(const struct ip6t_ip6 *ipv6)
180 {
181         if (ipv6->flags & ~IP6T_F_MASK) {
182                 duprintf("Unknown flag bits set: %08X\n",
183                          ipv6->flags & ~IP6T_F_MASK);
184                 return false;
185         }
186         if (ipv6->invflags & ~IP6T_INV_MASK) {
187                 duprintf("Unknown invflag bits set: %08X\n",
188                          ipv6->invflags & ~IP6T_INV_MASK);
189                 return false;
190         }
191         return true;
192 }
193
194 static unsigned int
195 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
196 {
197         if (net_ratelimit())
198                 pr_info("error: `%s'\n", (const char *)par->targinfo);
199
200         return NF_DROP;
201 }
202
203 static inline struct ip6t_entry *
204 get_entry(const void *base, unsigned int offset)
205 {
206         return (struct ip6t_entry *)(base + offset);
207 }
208
209 /* All zeroes == unconditional rule. */
210 /* Mildly perf critical (only if packet tracing is on) */
211 static inline bool unconditional(const struct ip6t_ip6 *ipv6)
212 {
213         static const struct ip6t_ip6 uncond;
214
215         return memcmp(ipv6, &uncond, sizeof(uncond)) == 0;
216 }
217
218 static inline const struct xt_entry_target *
219 ip6t_get_target_c(const struct ip6t_entry *e)
220 {
221         return ip6t_get_target((struct ip6t_entry *)e);
222 }
223
224 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
225     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
226 /* This cries for unification! */
227 static const char *const hooknames[] = {
228         [NF_INET_PRE_ROUTING]           = "PREROUTING",
229         [NF_INET_LOCAL_IN]              = "INPUT",
230         [NF_INET_FORWARD]               = "FORWARD",
231         [NF_INET_LOCAL_OUT]             = "OUTPUT",
232         [NF_INET_POST_ROUTING]          = "POSTROUTING",
233 };
234
235 enum nf_ip_trace_comments {
236         NF_IP6_TRACE_COMMENT_RULE,
237         NF_IP6_TRACE_COMMENT_RETURN,
238         NF_IP6_TRACE_COMMENT_POLICY,
239 };
240
241 static const char *const comments[] = {
242         [NF_IP6_TRACE_COMMENT_RULE]     = "rule",
243         [NF_IP6_TRACE_COMMENT_RETURN]   = "return",
244         [NF_IP6_TRACE_COMMENT_POLICY]   = "policy",
245 };
246
247 static struct nf_loginfo trace_loginfo = {
248         .type = NF_LOG_TYPE_LOG,
249         .u = {
250                 .log = {
251                         .level = 4,
252                         .logflags = NF_LOG_MASK,
253                 },
254         },
255 };
256
257 /* Mildly perf critical (only if packet tracing is on) */
258 static inline int
259 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
260                       const char *hookname, const char **chainname,
261                       const char **comment, unsigned int *rulenum)
262 {
263         const struct xt_standard_target *t = (void *)ip6t_get_target_c(s);
264
265         if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
266                 /* Head of user chain: ERROR target with chainname */
267                 *chainname = t->target.data;
268                 (*rulenum) = 0;
269         } else if (s == e) {
270                 (*rulenum)++;
271
272                 if (s->target_offset == sizeof(struct ip6t_entry) &&
273                     strcmp(t->target.u.kernel.target->name,
274                            XT_STANDARD_TARGET) == 0 &&
275                     t->verdict < 0 &&
276                     unconditional(&s->ipv6)) {
277                         /* Tail of chains: STANDARD target (return/policy) */
278                         *comment = *chainname == hookname
279                                 ? comments[NF_IP6_TRACE_COMMENT_POLICY]
280                                 : comments[NF_IP6_TRACE_COMMENT_RETURN];
281                 }
282                 return 1;
283         } else
284                 (*rulenum)++;
285
286         return 0;
287 }
288
289 static void trace_packet(const struct sk_buff *skb,
290                          unsigned int hook,
291                          const struct net_device *in,
292                          const struct net_device *out,
293                          const char *tablename,
294                          const struct xt_table_info *private,
295                          const struct ip6t_entry *e)
296 {
297         const void *table_base;
298         const struct ip6t_entry *root;
299         const char *hookname, *chainname, *comment;
300         const struct ip6t_entry *iter;
301         unsigned int rulenum = 0;
302
303         table_base = private->entries[smp_processor_id()];
304         root = get_entry(table_base, private->hook_entry[hook]);
305
306         hookname = chainname = hooknames[hook];
307         comment = comments[NF_IP6_TRACE_COMMENT_RULE];
308
309         xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
310                 if (get_chainname_rulenum(iter, e, hookname,
311                     &chainname, &comment, &rulenum) != 0)
312                         break;
313
314         nf_log_packet(AF_INET6, hook, skb, in, out, &trace_loginfo,
315                       "TRACE: %s:%s:%s:%u ",
316                       tablename, chainname, comment, rulenum);
317 }
318 #endif
319
320 static inline __pure struct ip6t_entry *
321 ip6t_next_entry(const struct ip6t_entry *entry)
322 {
323         return (void *)entry + entry->next_offset;
324 }
325
326 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
327 unsigned int
328 ip6t_do_table(struct sk_buff *skb,
329               unsigned int hook,
330               const struct net_device *in,
331               const struct net_device *out,
332               struct xt_table *table)
333 {
334         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
335         /* Initializing verdict to NF_DROP keeps gcc happy. */
336         unsigned int verdict = NF_DROP;
337         const char *indev, *outdev;
338         const void *table_base;
339         struct ip6t_entry *e, **jumpstack;
340         unsigned int *stackptr, origptr, cpu;
341         const struct xt_table_info *private;
342         struct xt_action_param acpar;
343         unsigned int addend;
344
345         /* Initialization */
346         indev = in ? in->name : nulldevname;
347         outdev = out ? out->name : nulldevname;
348         /* We handle fragments by dealing with the first fragment as
349          * if it was a normal packet.  All other fragments are treated
350          * normally, except that they will NEVER match rules that ask
351          * things we don't know, ie. tcp syn flag or ports).  If the
352          * rule is also a fragment-specific rule, non-fragments won't
353          * match it. */
354         acpar.hotdrop = false;
355         acpar.in      = in;
356         acpar.out     = out;
357         acpar.family  = NFPROTO_IPV6;
358         acpar.hooknum = hook;
359
360         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
361
362         local_bh_disable();
363         addend = xt_write_recseq_begin();
364         private = table->private;
365         cpu        = smp_processor_id();
366         table_base = private->entries[cpu];
367         jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
368         stackptr   = per_cpu_ptr(private->stackptr, cpu);
369         origptr    = *stackptr;
370
371         e = get_entry(table_base, private->hook_entry[hook]);
372
373         do {
374                 const struct xt_entry_target *t;
375                 const struct xt_entry_match *ematch;
376
377                 IP_NF_ASSERT(e);
378                 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
379                     &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) {
380  no_match:
381                         e = ip6t_next_entry(e);
382                         continue;
383                 }
384
385                 xt_ematch_foreach(ematch, e) {
386                         acpar.match     = ematch->u.kernel.match;
387                         acpar.matchinfo = ematch->data;
388                         if (!acpar.match->match(skb, &acpar))
389                                 goto no_match;
390                 }
391
392                 ADD_COUNTER(e->counters, skb->len, 1);
393
394                 t = ip6t_get_target_c(e);
395                 IP_NF_ASSERT(t->u.kernel.target);
396
397 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
398     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
399                 /* The packet is traced: log it */
400                 if (unlikely(skb->nf_trace))
401                         trace_packet(skb, hook, in, out,
402                                      table->name, private, e);
403 #endif
404                 /* Standard target? */
405                 if (!t->u.kernel.target->target) {
406                         int v;
407
408                         v = ((struct xt_standard_target *)t)->verdict;
409                         if (v < 0) {
410                                 /* Pop from stack? */
411                                 if (v != XT_RETURN) {
412                                         verdict = (unsigned)(-v) - 1;
413                                         break;
414                                 }
415                                 if (*stackptr <= origptr)
416                                         e = get_entry(table_base,
417                                             private->underflow[hook]);
418                                 else
419                                         e = ip6t_next_entry(jumpstack[--*stackptr]);
420                                 continue;
421                         }
422                         if (table_base + v != ip6t_next_entry(e) &&
423                             !(e->ipv6.flags & IP6T_F_GOTO)) {
424                                 if (*stackptr >= private->stacksize) {
425                                         verdict = NF_DROP;
426                                         break;
427                                 }
428                                 jumpstack[(*stackptr)++] = e;
429                         }
430
431                         e = get_entry(table_base, v);
432                         continue;
433                 }
434
435                 acpar.target   = t->u.kernel.target;
436                 acpar.targinfo = t->data;
437
438                 verdict = t->u.kernel.target->target(skb, &acpar);
439                 if (verdict == XT_CONTINUE)
440                         e = ip6t_next_entry(e);
441                 else
442                         /* Verdict */
443                         break;
444         } while (!acpar.hotdrop);
445
446         *stackptr = origptr;
447
448         xt_write_recseq_end(addend);
449         local_bh_enable();
450
451 #ifdef DEBUG_ALLOW_ALL
452         return NF_ACCEPT;
453 #else
454         if (acpar.hotdrop)
455                 return NF_DROP;
456         else return verdict;
457 #endif
458 }
459
460 /* Figures out from what hook each rule can be called: returns 0 if
461    there are loops.  Puts hook bitmask in comefrom. */
462 static int
463 mark_source_chains(const struct xt_table_info *newinfo,
464                    unsigned int valid_hooks, void *entry0)
465 {
466         unsigned int hook;
467
468         /* No recursion; use packet counter to save back ptrs (reset
469            to 0 as we leave), and comefrom to save source hook bitmask */
470         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
471                 unsigned int pos = newinfo->hook_entry[hook];
472                 struct ip6t_entry *e = (struct ip6t_entry *)(entry0 + pos);
473
474                 if (!(valid_hooks & (1 << hook)))
475                         continue;
476
477                 /* Set initial back pointer. */
478                 e->counters.pcnt = pos;
479
480                 for (;;) {
481                         const struct xt_standard_target *t
482                                 = (void *)ip6t_get_target_c(e);
483                         int visited = e->comefrom & (1 << hook);
484
485                         if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
486                                 pr_err("iptables: loop hook %u pos %u %08X.\n",
487                                        hook, pos, e->comefrom);
488                                 return 0;
489                         }
490                         e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
491
492                         /* Unconditional return/END. */
493                         if ((e->target_offset == sizeof(struct ip6t_entry) &&
494                              (strcmp(t->target.u.user.name,
495                                      XT_STANDARD_TARGET) == 0) &&
496                              t->verdict < 0 &&
497                              unconditional(&e->ipv6)) || visited) {
498                                 unsigned int oldpos, size;
499
500                                 if ((strcmp(t->target.u.user.name,
501                                             XT_STANDARD_TARGET) == 0) &&
502                                     t->verdict < -NF_MAX_VERDICT - 1) {
503                                         duprintf("mark_source_chains: bad "
504                                                 "negative verdict (%i)\n",
505                                                                 t->verdict);
506                                         return 0;
507                                 }
508
509                                 /* Return: backtrack through the last
510                                    big jump. */
511                                 do {
512                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
513 #ifdef DEBUG_IP_FIREWALL_USER
514                                         if (e->comefrom
515                                             & (1 << NF_INET_NUMHOOKS)) {
516                                                 duprintf("Back unset "
517                                                          "on hook %u "
518                                                          "rule %u\n",
519                                                          hook, pos);
520                                         }
521 #endif
522                                         oldpos = pos;
523                                         pos = e->counters.pcnt;
524                                         e->counters.pcnt = 0;
525
526                                         /* We're at the start. */
527                                         if (pos == oldpos)
528                                                 goto next;
529
530                                         e = (struct ip6t_entry *)
531                                                 (entry0 + pos);
532                                 } while (oldpos == pos + e->next_offset);
533
534                                 /* Move along one */
535                                 size = e->next_offset;
536                                 e = (struct ip6t_entry *)
537                                         (entry0 + pos + size);
538                                 e->counters.pcnt = pos;
539                                 pos += size;
540                         } else {
541                                 int newpos = t->verdict;
542
543                                 if (strcmp(t->target.u.user.name,
544                                            XT_STANDARD_TARGET) == 0 &&
545                                     newpos >= 0) {
546                                         if (newpos > newinfo->size -
547                                                 sizeof(struct ip6t_entry)) {
548                                                 duprintf("mark_source_chains: "
549                                                         "bad verdict (%i)\n",
550                                                                 newpos);
551                                                 return 0;
552                                         }
553                                         /* This a jump; chase it. */
554                                         duprintf("Jump rule %u -> %u\n",
555                                                  pos, newpos);
556                                 } else {
557                                         /* ... this is a fallthru */
558                                         newpos = pos + e->next_offset;
559                                 }
560                                 e = (struct ip6t_entry *)
561                                         (entry0 + newpos);
562                                 e->counters.pcnt = pos;
563                                 pos = newpos;
564                         }
565                 }
566                 next:
567                 duprintf("Finished chain %u\n", hook);
568         }
569         return 1;
570 }
571
572 static void cleanup_match(struct xt_entry_match *m, struct net *net)
573 {
574         struct xt_mtdtor_param par;
575
576         par.net       = net;
577         par.match     = m->u.kernel.match;
578         par.matchinfo = m->data;
579         par.family    = NFPROTO_IPV6;
580         if (par.match->destroy != NULL)
581                 par.match->destroy(&par);
582         module_put(par.match->me);
583 }
584
585 static int
586 check_entry(const struct ip6t_entry *e, const char *name)
587 {
588         const struct xt_entry_target *t;
589
590         if (!ip6_checkentry(&e->ipv6)) {
591                 duprintf("ip_tables: ip check failed %p %s.\n", e, name);
592                 return -EINVAL;
593         }
594
595         if (e->target_offset + sizeof(struct xt_entry_target) >
596             e->next_offset)
597                 return -EINVAL;
598
599         t = ip6t_get_target_c(e);
600         if (e->target_offset + t->u.target_size > e->next_offset)
601                 return -EINVAL;
602
603         return 0;
604 }
605
606 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
607 {
608         const struct ip6t_ip6 *ipv6 = par->entryinfo;
609         int ret;
610
611         par->match     = m->u.kernel.match;
612         par->matchinfo = m->data;
613
614         ret = xt_check_match(par, m->u.match_size - sizeof(*m),
615                              ipv6->proto, ipv6->invflags & IP6T_INV_PROTO);
616         if (ret < 0) {
617                 duprintf("ip_tables: check failed for `%s'.\n",
618                          par.match->name);
619                 return ret;
620         }
621         return 0;
622 }
623
624 static int
625 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
626 {
627         struct xt_match *match;
628         int ret;
629
630         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
631                                       m->u.user.revision);
632         if (IS_ERR(match)) {
633                 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
634                 return PTR_ERR(match);
635         }
636         m->u.kernel.match = match;
637
638         ret = check_match(m, par);
639         if (ret)
640                 goto err;
641
642         return 0;
643 err:
644         module_put(m->u.kernel.match->me);
645         return ret;
646 }
647
648 static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
649 {
650         struct xt_entry_target *t = ip6t_get_target(e);
651         struct xt_tgchk_param par = {
652                 .net       = net,
653                 .table     = name,
654                 .entryinfo = e,
655                 .target    = t->u.kernel.target,
656                 .targinfo  = t->data,
657                 .hook_mask = e->comefrom,
658                 .family    = NFPROTO_IPV6,
659         };
660         int ret;
661
662         t = ip6t_get_target(e);
663         ret = xt_check_target(&par, t->u.target_size - sizeof(*t),
664               e->ipv6.proto, e->ipv6.invflags & IP6T_INV_PROTO);
665         if (ret < 0) {
666                 duprintf("ip_tables: check failed for `%s'.\n",
667                          t->u.kernel.target->name);
668                 return ret;
669         }
670         return 0;
671 }
672
673 static int
674 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
675                  unsigned int size)
676 {
677         struct xt_entry_target *t;
678         struct xt_target *target;
679         int ret;
680         unsigned int j;
681         struct xt_mtchk_param mtpar;
682         struct xt_entry_match *ematch;
683
684         ret = check_entry(e, name);
685         if (ret)
686                 return ret;
687
688         j = 0;
689         mtpar.net       = net;
690         mtpar.table     = name;
691         mtpar.entryinfo = &e->ipv6;
692         mtpar.hook_mask = e->comefrom;
693         mtpar.family    = NFPROTO_IPV6;
694         xt_ematch_foreach(ematch, e) {
695                 ret = find_check_match(ematch, &mtpar);
696                 if (ret != 0)
697                         goto cleanup_matches;
698                 ++j;
699         }
700
701         t = ip6t_get_target(e);
702         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
703                                         t->u.user.revision);
704         if (IS_ERR(target)) {
705                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
706                 ret = PTR_ERR(target);
707                 goto cleanup_matches;
708         }
709         t->u.kernel.target = target;
710
711         ret = check_target(e, net, name);
712         if (ret)
713                 goto err;
714         return 0;
715  err:
716         module_put(t->u.kernel.target->me);
717  cleanup_matches:
718         xt_ematch_foreach(ematch, e) {
719                 if (j-- == 0)
720                         break;
721                 cleanup_match(ematch, net);
722         }
723         return ret;
724 }
725
726 static bool check_underflow(const struct ip6t_entry *e)
727 {
728         const struct xt_entry_target *t;
729         unsigned int verdict;
730
731         if (!unconditional(&e->ipv6))
732                 return false;
733         t = ip6t_get_target_c(e);
734         if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
735                 return false;
736         verdict = ((struct xt_standard_target *)t)->verdict;
737         verdict = -verdict - 1;
738         return verdict == NF_DROP || verdict == NF_ACCEPT;
739 }
740
741 static int
742 check_entry_size_and_hooks(struct ip6t_entry *e,
743                            struct xt_table_info *newinfo,
744                            const unsigned char *base,
745                            const unsigned char *limit,
746                            const unsigned int *hook_entries,
747                            const unsigned int *underflows,
748                            unsigned int valid_hooks)
749 {
750         unsigned int h;
751
752         if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
753             (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) {
754                 duprintf("Bad offset %p\n", e);
755                 return -EINVAL;
756         }
757
758         if (e->next_offset
759             < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) {
760                 duprintf("checking: element %p size %u\n",
761                          e, e->next_offset);
762                 return -EINVAL;
763         }
764
765         /* Check hooks & underflows */
766         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
767                 if (!(valid_hooks & (1 << h)))
768                         continue;
769                 if ((unsigned char *)e - base == hook_entries[h])
770                         newinfo->hook_entry[h] = hook_entries[h];
771                 if ((unsigned char *)e - base == underflows[h]) {
772                         if (!check_underflow(e)) {
773                                 pr_err("Underflows must be unconditional and "
774                                        "use the STANDARD target with "
775                                        "ACCEPT/DROP\n");
776                                 return -EINVAL;
777                         }
778                         newinfo->underflow[h] = underflows[h];
779                 }
780         }
781
782         /* Clear counters and comefrom */
783         e->counters = ((struct xt_counters) { 0, 0 });
784         e->comefrom = 0;
785         return 0;
786 }
787
788 static void cleanup_entry(struct ip6t_entry *e, struct net *net)
789 {
790         struct xt_tgdtor_param par;
791         struct xt_entry_target *t;
792         struct xt_entry_match *ematch;
793
794         /* Cleanup all matches */
795         xt_ematch_foreach(ematch, e)
796                 cleanup_match(ematch, net);
797         t = ip6t_get_target(e);
798
799         par.net      = net;
800         par.target   = t->u.kernel.target;
801         par.targinfo = t->data;
802         par.family   = NFPROTO_IPV6;
803         if (par.target->destroy != NULL)
804                 par.target->destroy(&par);
805         module_put(par.target->me);
806 }
807
808 /* Checks and translates the user-supplied table segment (held in
809    newinfo) */
810 static int
811 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
812                 const struct ip6t_replace *repl)
813 {
814         struct ip6t_entry *iter;
815         unsigned int i;
816         int ret = 0;
817
818         newinfo->size = repl->size;
819         newinfo->number = repl->num_entries;
820
821         /* Init all hooks to impossible value. */
822         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
823                 newinfo->hook_entry[i] = 0xFFFFFFFF;
824                 newinfo->underflow[i] = 0xFFFFFFFF;
825         }
826
827         duprintf("translate_table: size %u\n", newinfo->size);
828         i = 0;
829         /* Walk through entries, checking offsets. */
830         xt_entry_foreach(iter, entry0, newinfo->size) {
831                 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
832                                                  entry0 + repl->size,
833                                                  repl->hook_entry,
834                                                  repl->underflow,
835                                                  repl->valid_hooks);
836                 if (ret != 0)
837                         return ret;
838                 ++i;
839                 if (strcmp(ip6t_get_target(iter)->u.user.name,
840                     XT_ERROR_TARGET) == 0)
841                         ++newinfo->stacksize;
842         }
843
844         if (i != repl->num_entries) {
845                 duprintf("translate_table: %u not %u entries\n",
846                          i, repl->num_entries);
847                 return -EINVAL;
848         }
849
850         /* Check hooks all assigned */
851         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
852                 /* Only hooks which are valid */
853                 if (!(repl->valid_hooks & (1 << i)))
854                         continue;
855                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
856                         duprintf("Invalid hook entry %u %u\n",
857                                  i, repl->hook_entry[i]);
858                         return -EINVAL;
859                 }
860                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
861                         duprintf("Invalid underflow %u %u\n",
862                                  i, repl->underflow[i]);
863                         return -EINVAL;
864                 }
865         }
866
867         if (!mark_source_chains(newinfo, repl->valid_hooks, entry0))
868                 return -ELOOP;
869
870         /* Finally, each sanity check must pass */
871         i = 0;
872         xt_entry_foreach(iter, entry0, newinfo->size) {
873                 ret = find_check_entry(iter, net, repl->name, repl->size);
874                 if (ret != 0)
875                         break;
876                 ++i;
877         }
878
879         if (ret != 0) {
880                 xt_entry_foreach(iter, entry0, newinfo->size) {
881                         if (i-- == 0)
882                                 break;
883                         cleanup_entry(iter, net);
884                 }
885                 return ret;
886         }
887
888         /* And one copy for every other CPU */
889         for_each_possible_cpu(i) {
890                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
891                         memcpy(newinfo->entries[i], entry0, newinfo->size);
892         }
893
894         return ret;
895 }
896
897 static void
898 get_counters(const struct xt_table_info *t,
899              struct xt_counters counters[])
900 {
901         struct ip6t_entry *iter;
902         unsigned int cpu;
903         unsigned int i;
904
905         for_each_possible_cpu(cpu) {
906                 seqcount_t *s = &per_cpu(xt_recseq, cpu);
907
908                 i = 0;
909                 xt_entry_foreach(iter, t->entries[cpu], t->size) {
910                         u64 bcnt, pcnt;
911                         unsigned int start;
912
913                         do {
914                                 start = read_seqcount_begin(s);
915                                 bcnt = iter->counters.bcnt;
916                                 pcnt = iter->counters.pcnt;
917                         } while (read_seqcount_retry(s, start));
918
919                         ADD_COUNTER(counters[i], bcnt, pcnt);
920                         ++i;
921                 }
922         }
923 }
924
925 static struct xt_counters *alloc_counters(const struct xt_table *table)
926 {
927         unsigned int countersize;
928         struct xt_counters *counters;
929         const struct xt_table_info *private = table->private;
930
931         /* We need atomic snapshot of counters: rest doesn't change
932            (other than comefrom, which userspace doesn't care
933            about). */
934         countersize = sizeof(struct xt_counters) * private->number;
935         counters = vzalloc(countersize);
936
937         if (counters == NULL)
938                 return ERR_PTR(-ENOMEM);
939
940         get_counters(private, counters);
941
942         return counters;
943 }
944
945 static int
946 copy_entries_to_user(unsigned int total_size,
947                      const struct xt_table *table,
948                      void __user *userptr)
949 {
950         unsigned int off, num;
951         const struct ip6t_entry *e;
952         struct xt_counters *counters;
953         const struct xt_table_info *private = table->private;
954         int ret = 0;
955         const void *loc_cpu_entry;
956
957         counters = alloc_counters(table);
958         if (IS_ERR(counters))
959                 return PTR_ERR(counters);
960
961         /* choose the copy that is on our node/cpu, ...
962          * This choice is lazy (because current thread is
963          * allowed to migrate to another cpu)
964          */
965         loc_cpu_entry = private->entries[raw_smp_processor_id()];
966         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
967                 ret = -EFAULT;
968                 goto free_counters;
969         }
970
971         /* FIXME: use iterator macros --RR */
972         /* ... then go back and fix counters and names */
973         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
974                 unsigned int i;
975                 const struct xt_entry_match *m;
976                 const struct xt_entry_target *t;
977
978                 e = (struct ip6t_entry *)(loc_cpu_entry + off);
979                 if (copy_to_user(userptr + off
980                                  + offsetof(struct ip6t_entry, counters),
981                                  &counters[num],
982                                  sizeof(counters[num])) != 0) {
983                         ret = -EFAULT;
984                         goto free_counters;
985                 }
986
987                 for (i = sizeof(struct ip6t_entry);
988                      i < e->target_offset;
989                      i += m->u.match_size) {
990                         m = (void *)e + i;
991
992                         if (copy_to_user(userptr + off + i
993                                          + offsetof(struct xt_entry_match,
994                                                     u.user.name),
995                                          m->u.kernel.match->name,
996                                          strlen(m->u.kernel.match->name)+1)
997                             != 0) {
998                                 ret = -EFAULT;
999                                 goto free_counters;
1000                         }
1001                 }
1002
1003                 t = ip6t_get_target_c(e);
1004                 if (copy_to_user(userptr + off + e->target_offset
1005                                  + offsetof(struct xt_entry_target,
1006                                             u.user.name),
1007                                  t->u.kernel.target->name,
1008                                  strlen(t->u.kernel.target->name)+1) != 0) {
1009                         ret = -EFAULT;
1010                         goto free_counters;
1011                 }
1012         }
1013
1014  free_counters:
1015         vfree(counters);
1016         return ret;
1017 }
1018
1019 #ifdef CONFIG_COMPAT
1020 static void compat_standard_from_user(void *dst, const void *src)
1021 {
1022         int v = *(compat_int_t *)src;
1023
1024         if (v > 0)
1025                 v += xt_compat_calc_jump(AF_INET6, v);
1026         memcpy(dst, &v, sizeof(v));
1027 }
1028
1029 static int compat_standard_to_user(void __user *dst, const void *src)
1030 {
1031         compat_int_t cv = *(int *)src;
1032
1033         if (cv > 0)
1034                 cv -= xt_compat_calc_jump(AF_INET6, cv);
1035         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
1036 }
1037
1038 static int compat_calc_entry(const struct ip6t_entry *e,
1039                              const struct xt_table_info *info,
1040                              const void *base, struct xt_table_info *newinfo)
1041 {
1042         const struct xt_entry_match *ematch;
1043         const struct xt_entry_target *t;
1044         unsigned int entry_offset;
1045         int off, i, ret;
1046
1047         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1048         entry_offset = (void *)e - base;
1049         xt_ematch_foreach(ematch, e)
1050                 off += xt_compat_match_offset(ematch->u.kernel.match);
1051         t = ip6t_get_target_c(e);
1052         off += xt_compat_target_offset(t->u.kernel.target);
1053         newinfo->size -= off;
1054         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
1055         if (ret)
1056                 return ret;
1057
1058         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1059                 if (info->hook_entry[i] &&
1060                     (e < (struct ip6t_entry *)(base + info->hook_entry[i])))
1061                         newinfo->hook_entry[i] -= off;
1062                 if (info->underflow[i] &&
1063                     (e < (struct ip6t_entry *)(base + info->underflow[i])))
1064                         newinfo->underflow[i] -= off;
1065         }
1066         return 0;
1067 }
1068
1069 static int compat_table_info(const struct xt_table_info *info,
1070                              struct xt_table_info *newinfo)
1071 {
1072         struct ip6t_entry *iter;
1073         void *loc_cpu_entry;
1074         int ret;
1075
1076         if (!newinfo || !info)
1077                 return -EINVAL;
1078
1079         /* we dont care about newinfo->entries[] */
1080         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
1081         newinfo->initial_entries = 0;
1082         loc_cpu_entry = info->entries[raw_smp_processor_id()];
1083         xt_compat_init_offsets(AF_INET6, info->number);
1084         xt_entry_foreach(iter, loc_cpu_entry, info->size) {
1085                 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
1086                 if (ret != 0)
1087                         return ret;
1088         }
1089         return 0;
1090 }
1091 #endif
1092
1093 static int get_info(struct net *net, void __user *user,
1094                     const int *len, int compat)
1095 {
1096         char name[XT_TABLE_MAXNAMELEN];
1097         struct xt_table *t;
1098         int ret;
1099
1100         if (*len != sizeof(struct ip6t_getinfo)) {
1101                 duprintf("length %u != %zu\n", *len,
1102                          sizeof(struct ip6t_getinfo));
1103                 return -EINVAL;
1104         }
1105
1106         if (copy_from_user(name, user, sizeof(name)) != 0)
1107                 return -EFAULT;
1108
1109         name[XT_TABLE_MAXNAMELEN-1] = '\0';
1110 #ifdef CONFIG_COMPAT
1111         if (compat)
1112                 xt_compat_lock(AF_INET6);
1113 #endif
1114         t = try_then_request_module(xt_find_table_lock(net, AF_INET6, name),
1115                                     "ip6table_%s", name);
1116         if (t && !IS_ERR(t)) {
1117                 struct ip6t_getinfo info;
1118                 const struct xt_table_info *private = t->private;
1119 #ifdef CONFIG_COMPAT
1120                 struct xt_table_info tmp;
1121
1122                 if (compat) {
1123                         ret = compat_table_info(private, &tmp);
1124                         xt_compat_flush_offsets(AF_INET6);
1125                         private = &tmp;
1126                 }
1127 #endif
1128                 memset(&info, 0, sizeof(info));
1129                 info.valid_hooks = t->valid_hooks;
1130                 memcpy(info.hook_entry, private->hook_entry,
1131                        sizeof(info.hook_entry));
1132                 memcpy(info.underflow, private->underflow,
1133                        sizeof(info.underflow));
1134                 info.num_entries = private->number;
1135                 info.size = private->size;
1136                 strcpy(info.name, name);
1137
1138                 if (copy_to_user(user, &info, *len) != 0)
1139                         ret = -EFAULT;
1140                 else
1141                         ret = 0;
1142
1143                 xt_table_unlock(t);
1144                 module_put(t->me);
1145         } else
1146                 ret = t ? PTR_ERR(t) : -ENOENT;
1147 #ifdef CONFIG_COMPAT
1148         if (compat)
1149                 xt_compat_unlock(AF_INET6);
1150 #endif
1151         return ret;
1152 }
1153
1154 static int
1155 get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
1156             const int *len)
1157 {
1158         int ret;
1159         struct ip6t_get_entries get;
1160         struct xt_table *t;
1161
1162         if (*len < sizeof(get)) {
1163                 duprintf("get_entries: %u < %zu\n", *len, sizeof(get));
1164                 return -EINVAL;
1165         }
1166         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1167                 return -EFAULT;
1168         if (*len != sizeof(struct ip6t_get_entries) + get.size) {
1169                 duprintf("get_entries: %u != %zu\n",
1170                          *len, sizeof(get) + get.size);
1171                 return -EINVAL;
1172         }
1173
1174         t = xt_find_table_lock(net, AF_INET6, get.name);
1175         if (t && !IS_ERR(t)) {
1176                 struct xt_table_info *private = t->private;
1177                 duprintf("t->private->number = %u\n", private->number);
1178                 if (get.size == private->size)
1179                         ret = copy_entries_to_user(private->size,
1180                                                    t, uptr->entrytable);
1181                 else {
1182                         duprintf("get_entries: I've got %u not %u!\n",
1183                                  private->size, get.size);
1184                         ret = -EAGAIN;
1185                 }
1186                 module_put(t->me);
1187                 xt_table_unlock(t);
1188         } else
1189                 ret = t ? PTR_ERR(t) : -ENOENT;
1190
1191         return ret;
1192 }
1193
1194 static int
1195 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1196              struct xt_table_info *newinfo, unsigned int num_counters,
1197              void __user *counters_ptr)
1198 {
1199         int ret;
1200         struct xt_table *t;
1201         struct xt_table_info *oldinfo;
1202         struct xt_counters *counters;
1203         const void *loc_cpu_old_entry;
1204         struct ip6t_entry *iter;
1205
1206         ret = 0;
1207         counters = vzalloc(num_counters * sizeof(struct xt_counters));
1208         if (!counters) {
1209                 ret = -ENOMEM;
1210                 goto out;
1211         }
1212
1213         t = try_then_request_module(xt_find_table_lock(net, AF_INET6, name),
1214                                     "ip6table_%s", name);
1215         if (!t || IS_ERR(t)) {
1216                 ret = t ? PTR_ERR(t) : -ENOENT;
1217                 goto free_newinfo_counters_untrans;
1218         }
1219
1220         /* You lied! */
1221         if (valid_hooks != t->valid_hooks) {
1222                 duprintf("Valid hook crap: %08X vs %08X\n",
1223                          valid_hooks, t->valid_hooks);
1224                 ret = -EINVAL;
1225                 goto put_module;
1226         }
1227
1228         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1229         if (!oldinfo)
1230                 goto put_module;
1231
1232         /* Update module usage count based on number of rules */
1233         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1234                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1235         if ((oldinfo->number > oldinfo->initial_entries) ||
1236             (newinfo->number <= oldinfo->initial_entries))
1237                 module_put(t->me);
1238         if ((oldinfo->number > oldinfo->initial_entries) &&
1239             (newinfo->number <= oldinfo->initial_entries))
1240                 module_put(t->me);
1241
1242         /* Get the old counters, and synchronize with replace */
1243         get_counters(oldinfo, counters);
1244
1245         /* Decrease module usage counts and free resource */
1246         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1247         xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1248                 cleanup_entry(iter, net);
1249
1250         xt_free_table_info(oldinfo);
1251         if (copy_to_user(counters_ptr, counters,
1252                          sizeof(struct xt_counters) * num_counters) != 0)
1253                 ret = -EFAULT;
1254         vfree(counters);
1255         xt_table_unlock(t);
1256         return ret;
1257
1258  put_module:
1259         module_put(t->me);
1260         xt_table_unlock(t);
1261  free_newinfo_counters_untrans:
1262         vfree(counters);
1263  out:
1264         return ret;
1265 }
1266
1267 static int
1268 do_replace(struct net *net, const void __user *user, unsigned int len)
1269 {
1270         int ret;
1271         struct ip6t_replace tmp;
1272         struct xt_table_info *newinfo;
1273         void *loc_cpu_entry;
1274         struct ip6t_entry *iter;
1275
1276         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1277                 return -EFAULT;
1278
1279         /* overflow check */
1280         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1281                 return -ENOMEM;
1282         tmp.name[sizeof(tmp.name)-1] = 0;
1283
1284         newinfo = xt_alloc_table_info(tmp.size);
1285         if (!newinfo)
1286                 return -ENOMEM;
1287
1288         /* choose the copy that is on our node/cpu */
1289         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1290         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1291                            tmp.size) != 0) {
1292                 ret = -EFAULT;
1293                 goto free_newinfo;
1294         }
1295
1296         ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1297         if (ret != 0)
1298                 goto free_newinfo;
1299
1300         duprintf("ip_tables: Translated table\n");
1301
1302         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1303                            tmp.num_counters, tmp.counters);
1304         if (ret)
1305                 goto free_newinfo_untrans;
1306         return 0;
1307
1308  free_newinfo_untrans:
1309         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1310                 cleanup_entry(iter, net);
1311  free_newinfo:
1312         xt_free_table_info(newinfo);
1313         return ret;
1314 }
1315
1316 static int
1317 do_add_counters(struct net *net, const void __user *user, unsigned int len,
1318                 int compat)
1319 {
1320         unsigned int i, curcpu;
1321         struct xt_counters_info tmp;
1322         struct xt_counters *paddc;
1323         unsigned int num_counters;
1324         char *name;
1325         int size;
1326         void *ptmp;
1327         struct xt_table *t;
1328         const struct xt_table_info *private;
1329         int ret = 0;
1330         const void *loc_cpu_entry;
1331         struct ip6t_entry *iter;
1332         unsigned int addend;
1333 #ifdef CONFIG_COMPAT
1334         struct compat_xt_counters_info compat_tmp;
1335
1336         if (compat) {
1337                 ptmp = &compat_tmp;
1338                 size = sizeof(struct compat_xt_counters_info);
1339         } else
1340 #endif
1341         {
1342                 ptmp = &tmp;
1343                 size = sizeof(struct xt_counters_info);
1344         }
1345
1346         if (copy_from_user(ptmp, user, size) != 0)
1347                 return -EFAULT;
1348
1349 #ifdef CONFIG_COMPAT
1350         if (compat) {
1351                 num_counters = compat_tmp.num_counters;
1352                 name = compat_tmp.name;
1353         } else
1354 #endif
1355         {
1356                 num_counters = tmp.num_counters;
1357                 name = tmp.name;
1358         }
1359
1360         if (len != size + num_counters * sizeof(struct xt_counters))
1361                 return -EINVAL;
1362
1363         paddc = vmalloc(len - size);
1364         if (!paddc)
1365                 return -ENOMEM;
1366
1367         if (copy_from_user(paddc, user + size, len - size) != 0) {
1368                 ret = -EFAULT;
1369                 goto free;
1370         }
1371
1372         t = xt_find_table_lock(net, AF_INET6, name);
1373         if (!t || IS_ERR(t)) {
1374                 ret = t ? PTR_ERR(t) : -ENOENT;
1375                 goto free;
1376         }
1377
1378
1379         local_bh_disable();
1380         private = t->private;
1381         if (private->number != num_counters) {
1382                 ret = -EINVAL;
1383                 goto unlock_up_free;
1384         }
1385
1386         i = 0;
1387         /* Choose the copy that is on our node */
1388         curcpu = smp_processor_id();
1389         addend = xt_write_recseq_begin();
1390         loc_cpu_entry = private->entries[curcpu];
1391         xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1392                 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1393                 ++i;
1394         }
1395         xt_write_recseq_end(addend);
1396
1397  unlock_up_free:
1398         local_bh_enable();
1399         xt_table_unlock(t);
1400         module_put(t->me);
1401  free:
1402         vfree(paddc);
1403
1404         return ret;
1405 }
1406
1407 #ifdef CONFIG_COMPAT
1408 struct compat_ip6t_replace {
1409         char                    name[XT_TABLE_MAXNAMELEN];
1410         u32                     valid_hooks;
1411         u32                     num_entries;
1412         u32                     size;
1413         u32                     hook_entry[NF_INET_NUMHOOKS];
1414         u32                     underflow[NF_INET_NUMHOOKS];
1415         u32                     num_counters;
1416         compat_uptr_t           counters;       /* struct xt_counters * */
1417         struct compat_ip6t_entry entries[0];
1418 };
1419
1420 static int
1421 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
1422                           unsigned int *size, struct xt_counters *counters,
1423                           unsigned int i)
1424 {
1425         struct xt_entry_target *t;
1426         struct compat_ip6t_entry __user *ce;
1427         u_int16_t target_offset, next_offset;
1428         compat_uint_t origsize;
1429         const struct xt_entry_match *ematch;
1430         int ret = 0;
1431
1432         origsize = *size;
1433         ce = (struct compat_ip6t_entry __user *)*dstptr;
1434         if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 ||
1435             copy_to_user(&ce->counters, &counters[i],
1436             sizeof(counters[i])) != 0)
1437                 return -EFAULT;
1438
1439         *dstptr += sizeof(struct compat_ip6t_entry);
1440         *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1441
1442         xt_ematch_foreach(ematch, e) {
1443                 ret = xt_compat_match_to_user(ematch, dstptr, size);
1444                 if (ret != 0)
1445                         return ret;
1446         }
1447         target_offset = e->target_offset - (origsize - *size);
1448         t = ip6t_get_target(e);
1449         ret = xt_compat_target_to_user(t, dstptr, size);
1450         if (ret)
1451                 return ret;
1452         next_offset = e->next_offset - (origsize - *size);
1453         if (put_user(target_offset, &ce->target_offset) != 0 ||
1454             put_user(next_offset, &ce->next_offset) != 0)
1455                 return -EFAULT;
1456         return 0;
1457 }
1458
1459 static int
1460 compat_find_calc_match(struct xt_entry_match *m,
1461                        const char *name,
1462                        const struct ip6t_ip6 *ipv6,
1463                        unsigned int hookmask,
1464                        int *size)
1465 {
1466         struct xt_match *match;
1467
1468         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
1469                                       m->u.user.revision);
1470         if (IS_ERR(match)) {
1471                 duprintf("compat_check_calc_match: `%s' not found\n",
1472                          m->u.user.name);
1473                 return PTR_ERR(match);
1474         }
1475         m->u.kernel.match = match;
1476         *size += xt_compat_match_offset(match);
1477         return 0;
1478 }
1479
1480 static void compat_release_entry(struct compat_ip6t_entry *e)
1481 {
1482         struct xt_entry_target *t;
1483         struct xt_entry_match *ematch;
1484
1485         /* Cleanup all matches */
1486         xt_ematch_foreach(ematch, e)
1487                 module_put(ematch->u.kernel.match->me);
1488         t = compat_ip6t_get_target(e);
1489         module_put(t->u.kernel.target->me);
1490 }
1491
1492 static int
1493 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
1494                                   struct xt_table_info *newinfo,
1495                                   unsigned int *size,
1496                                   const unsigned char *base,
1497                                   const unsigned char *limit,
1498                                   const unsigned int *hook_entries,
1499                                   const unsigned int *underflows,
1500                                   const char *name)
1501 {
1502         struct xt_entry_match *ematch;
1503         struct xt_entry_target *t;
1504         struct xt_target *target;
1505         unsigned int entry_offset;
1506         unsigned int j;
1507         int ret, off, h;
1508
1509         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1510         if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
1511             (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit) {
1512                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1513                 return -EINVAL;
1514         }
1515
1516         if (e->next_offset < sizeof(struct compat_ip6t_entry) +
1517                              sizeof(struct compat_xt_entry_target)) {
1518                 duprintf("checking: element %p size %u\n",
1519                          e, e->next_offset);
1520                 return -EINVAL;
1521         }
1522
1523         /* For purposes of check_entry casting the compat entry is fine */
1524         ret = check_entry((struct ip6t_entry *)e, name);
1525         if (ret)
1526                 return ret;
1527
1528         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1529         entry_offset = (void *)e - (void *)base;
1530         j = 0;
1531         xt_ematch_foreach(ematch, e) {
1532                 ret = compat_find_calc_match(ematch, name,
1533                                              &e->ipv6, e->comefrom, &off);
1534                 if (ret != 0)
1535                         goto release_matches;
1536                 ++j;
1537         }
1538
1539         t = compat_ip6t_get_target(e);
1540         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
1541                                         t->u.user.revision);
1542         if (IS_ERR(target)) {
1543                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1544                          t->u.user.name);
1545                 ret = PTR_ERR(target);
1546                 goto release_matches;
1547         }
1548         t->u.kernel.target = target;
1549
1550         off += xt_compat_target_offset(target);
1551         *size += off;
1552         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
1553         if (ret)
1554                 goto out;
1555
1556         /* Check hooks & underflows */
1557         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1558                 if ((unsigned char *)e - base == hook_entries[h])
1559                         newinfo->hook_entry[h] = hook_entries[h];
1560                 if ((unsigned char *)e - base == underflows[h])
1561                         newinfo->underflow[h] = underflows[h];
1562         }
1563
1564         /* Clear counters and comefrom */
1565         memset(&e->counters, 0, sizeof(e->counters));
1566         e->comefrom = 0;
1567         return 0;
1568
1569 out:
1570         module_put(t->u.kernel.target->me);
1571 release_matches:
1572         xt_ematch_foreach(ematch, e) {
1573                 if (j-- == 0)
1574                         break;
1575                 module_put(ematch->u.kernel.match->me);
1576         }
1577         return ret;
1578 }
1579
1580 static int
1581 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
1582                             unsigned int *size, const char *name,
1583                             struct xt_table_info *newinfo, unsigned char *base)
1584 {
1585         struct xt_entry_target *t;
1586         struct ip6t_entry *de;
1587         unsigned int origsize;
1588         int ret, h;
1589         struct xt_entry_match *ematch;
1590
1591         ret = 0;
1592         origsize = *size;
1593         de = (struct ip6t_entry *)*dstptr;
1594         memcpy(de, e, sizeof(struct ip6t_entry));
1595         memcpy(&de->counters, &e->counters, sizeof(e->counters));
1596
1597         *dstptr += sizeof(struct ip6t_entry);
1598         *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1599
1600         xt_ematch_foreach(ematch, e) {
1601                 ret = xt_compat_match_from_user(ematch, dstptr, size);
1602                 if (ret != 0)
1603                         return ret;
1604         }
1605         de->target_offset = e->target_offset - (origsize - *size);
1606         t = compat_ip6t_get_target(e);
1607         xt_compat_target_from_user(t, dstptr, size);
1608
1609         de->next_offset = e->next_offset - (origsize - *size);
1610         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1611                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1612                         newinfo->hook_entry[h] -= origsize - *size;
1613                 if ((unsigned char *)de - base < newinfo->underflow[h])
1614                         newinfo->underflow[h] -= origsize - *size;
1615         }
1616         return ret;
1617 }
1618
1619 static int compat_check_entry(struct ip6t_entry *e, struct net *net,
1620                               const char *name)
1621 {
1622         unsigned int j;
1623         int ret = 0;
1624         struct xt_mtchk_param mtpar;
1625         struct xt_entry_match *ematch;
1626
1627         j = 0;
1628         mtpar.net       = net;
1629         mtpar.table     = name;
1630         mtpar.entryinfo = &e->ipv6;
1631         mtpar.hook_mask = e->comefrom;
1632         mtpar.family    = NFPROTO_IPV6;
1633         xt_ematch_foreach(ematch, e) {
1634                 ret = check_match(ematch, &mtpar);
1635                 if (ret != 0)
1636                         goto cleanup_matches;
1637                 ++j;
1638         }
1639
1640         ret = check_target(e, net, name);
1641         if (ret)
1642                 goto cleanup_matches;
1643         return 0;
1644
1645  cleanup_matches:
1646         xt_ematch_foreach(ematch, e) {
1647                 if (j-- == 0)
1648                         break;
1649                 cleanup_match(ematch, net);
1650         }
1651         return ret;
1652 }
1653
1654 static int
1655 translate_compat_table(struct net *net,
1656                        const char *name,
1657                        unsigned int valid_hooks,
1658                        struct xt_table_info **pinfo,
1659                        void **pentry0,
1660                        unsigned int total_size,
1661                        unsigned int number,
1662                        unsigned int *hook_entries,
1663                        unsigned int *underflows)
1664 {
1665         unsigned int i, j;
1666         struct xt_table_info *newinfo, *info;
1667         void *pos, *entry0, *entry1;
1668         struct compat_ip6t_entry *iter0;
1669         struct ip6t_entry *iter1;
1670         unsigned int size;
1671         int ret = 0;
1672
1673         info = *pinfo;
1674         entry0 = *pentry0;
1675         size = total_size;
1676         info->number = number;
1677
1678         /* Init all hooks to impossible value. */
1679         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1680                 info->hook_entry[i] = 0xFFFFFFFF;
1681                 info->underflow[i] = 0xFFFFFFFF;
1682         }
1683
1684         duprintf("translate_compat_table: size %u\n", info->size);
1685         j = 0;
1686         xt_compat_lock(AF_INET6);
1687         xt_compat_init_offsets(AF_INET6, number);
1688         /* Walk through entries, checking offsets. */
1689         xt_entry_foreach(iter0, entry0, total_size) {
1690                 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1691                                                         entry0,
1692                                                         entry0 + total_size,
1693                                                         hook_entries,
1694                                                         underflows,
1695                                                         name);
1696                 if (ret != 0)
1697                         goto out_unlock;
1698                 ++j;
1699         }
1700
1701         ret = -EINVAL;
1702         if (j != number) {
1703                 duprintf("translate_compat_table: %u not %u entries\n",
1704                          j, number);
1705                 goto out_unlock;
1706         }
1707
1708         /* Check hooks all assigned */
1709         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1710                 /* Only hooks which are valid */
1711                 if (!(valid_hooks & (1 << i)))
1712                         continue;
1713                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1714                         duprintf("Invalid hook entry %u %u\n",
1715                                  i, hook_entries[i]);
1716                         goto out_unlock;
1717                 }
1718                 if (info->underflow[i] == 0xFFFFFFFF) {
1719                         duprintf("Invalid underflow %u %u\n",
1720                                  i, underflows[i]);
1721                         goto out_unlock;
1722                 }
1723         }
1724
1725         ret = -ENOMEM;
1726         newinfo = xt_alloc_table_info(size);
1727         if (!newinfo)
1728                 goto out_unlock;
1729
1730         newinfo->number = number;
1731         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1732                 newinfo->hook_entry[i] = info->hook_entry[i];
1733                 newinfo->underflow[i] = info->underflow[i];
1734         }
1735         entry1 = newinfo->entries[raw_smp_processor_id()];
1736         pos = entry1;
1737         size = total_size;
1738         xt_entry_foreach(iter0, entry0, total_size) {
1739                 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1740                                                   name, newinfo, entry1);
1741                 if (ret != 0)
1742                         break;
1743         }
1744         xt_compat_flush_offsets(AF_INET6);
1745         xt_compat_unlock(AF_INET6);
1746         if (ret)
1747                 goto free_newinfo;
1748
1749         ret = -ELOOP;
1750         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1751                 goto free_newinfo;
1752
1753         i = 0;
1754         xt_entry_foreach(iter1, entry1, newinfo->size) {
1755                 ret = compat_check_entry(iter1, net, name);
1756                 if (ret != 0)
1757                         break;
1758                 ++i;
1759                 if (strcmp(ip6t_get_target(iter1)->u.user.name,
1760                     XT_ERROR_TARGET) == 0)
1761                         ++newinfo->stacksize;
1762         }
1763         if (ret) {
1764                 /*
1765                  * The first i matches need cleanup_entry (calls ->destroy)
1766                  * because they had called ->check already. The other j-i
1767                  * entries need only release.
1768                  */
1769                 int skip = i;
1770                 j -= i;
1771                 xt_entry_foreach(iter0, entry0, newinfo->size) {
1772                         if (skip-- > 0)
1773                                 continue;
1774                         if (j-- == 0)
1775                                 break;
1776                         compat_release_entry(iter0);
1777                 }
1778                 xt_entry_foreach(iter1, entry1, newinfo->size) {
1779                         if (i-- == 0)
1780                                 break;
1781                         cleanup_entry(iter1, net);
1782                 }
1783                 xt_free_table_info(newinfo);
1784                 return ret;
1785         }
1786
1787         /* And one copy for every other CPU */
1788         for_each_possible_cpu(i)
1789                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1790                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1791
1792         *pinfo = newinfo;
1793         *pentry0 = entry1;
1794         xt_free_table_info(info);
1795         return 0;
1796
1797 free_newinfo:
1798         xt_free_table_info(newinfo);
1799 out:
1800         xt_entry_foreach(iter0, entry0, total_size) {
1801                 if (j-- == 0)
1802                         break;
1803                 compat_release_entry(iter0);
1804         }
1805         return ret;
1806 out_unlock:
1807         xt_compat_flush_offsets(AF_INET6);
1808         xt_compat_unlock(AF_INET6);
1809         goto out;
1810 }
1811
1812 static int
1813 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1814 {
1815         int ret;
1816         struct compat_ip6t_replace tmp;
1817         struct xt_table_info *newinfo;
1818         void *loc_cpu_entry;
1819         struct ip6t_entry *iter;
1820
1821         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1822                 return -EFAULT;
1823
1824         /* overflow check */
1825         if (tmp.size >= INT_MAX / num_possible_cpus())
1826                 return -ENOMEM;
1827         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1828                 return -ENOMEM;
1829         tmp.name[sizeof(tmp.name)-1] = 0;
1830
1831         newinfo = xt_alloc_table_info(tmp.size);
1832         if (!newinfo)
1833                 return -ENOMEM;
1834
1835         /* choose the copy that is on our node/cpu */
1836         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1837         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1838                            tmp.size) != 0) {
1839                 ret = -EFAULT;
1840                 goto free_newinfo;
1841         }
1842
1843         ret = translate_compat_table(net, tmp.name, tmp.valid_hooks,
1844                                      &newinfo, &loc_cpu_entry, tmp.size,
1845                                      tmp.num_entries, tmp.hook_entry,
1846                                      tmp.underflow);
1847         if (ret != 0)
1848                 goto free_newinfo;
1849
1850         duprintf("compat_do_replace: Translated table\n");
1851
1852         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1853                            tmp.num_counters, compat_ptr(tmp.counters));
1854         if (ret)
1855                 goto free_newinfo_untrans;
1856         return 0;
1857
1858  free_newinfo_untrans:
1859         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1860                 cleanup_entry(iter, net);
1861  free_newinfo:
1862         xt_free_table_info(newinfo);
1863         return ret;
1864 }
1865
1866 static int
1867 compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user,
1868                        unsigned int len)
1869 {
1870         int ret;
1871
1872         if (!capable(CAP_NET_ADMIN))
1873                 return -EPERM;
1874
1875         switch (cmd) {
1876         case IP6T_SO_SET_REPLACE:
1877                 ret = compat_do_replace(sock_net(sk), user, len);
1878                 break;
1879
1880         case IP6T_SO_SET_ADD_COUNTERS:
1881                 ret = do_add_counters(sock_net(sk), user, len, 1);
1882                 break;
1883
1884         default:
1885                 duprintf("do_ip6t_set_ctl:  unknown request %i\n", cmd);
1886                 ret = -EINVAL;
1887         }
1888
1889         return ret;
1890 }
1891
1892 struct compat_ip6t_get_entries {
1893         char name[XT_TABLE_MAXNAMELEN];
1894         compat_uint_t size;
1895         struct compat_ip6t_entry entrytable[0];
1896 };
1897
1898 static int
1899 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1900                             void __user *userptr)
1901 {
1902         struct xt_counters *counters;
1903         const struct xt_table_info *private = table->private;
1904         void __user *pos;
1905         unsigned int size;
1906         int ret = 0;
1907         const void *loc_cpu_entry;
1908         unsigned int i = 0;
1909         struct ip6t_entry *iter;
1910
1911         counters = alloc_counters(table);
1912         if (IS_ERR(counters))
1913                 return PTR_ERR(counters);
1914
1915         /* choose the copy that is on our node/cpu, ...
1916          * This choice is lazy (because current thread is
1917          * allowed to migrate to another cpu)
1918          */
1919         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1920         pos = userptr;
1921         size = total_size;
1922         xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1923                 ret = compat_copy_entry_to_user(iter, &pos,
1924                                                 &size, counters, i++);
1925                 if (ret != 0)
1926                         break;
1927         }
1928
1929         vfree(counters);
1930         return ret;
1931 }
1932
1933 static int
1934 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
1935                    int *len)
1936 {
1937         int ret;
1938         struct compat_ip6t_get_entries get;
1939         struct xt_table *t;
1940
1941         if (*len < sizeof(get)) {
1942                 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1943                 return -EINVAL;
1944         }
1945
1946         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1947                 return -EFAULT;
1948
1949         if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) {
1950                 duprintf("compat_get_entries: %u != %zu\n",
1951                          *len, sizeof(get) + get.size);
1952                 return -EINVAL;
1953         }
1954
1955         xt_compat_lock(AF_INET6);
1956         t = xt_find_table_lock(net, AF_INET6, get.name);
1957         if (t && !IS_ERR(t)) {
1958                 const struct xt_table_info *private = t->private;
1959                 struct xt_table_info info;
1960                 duprintf("t->private->number = %u\n", private->number);
1961                 ret = compat_table_info(private, &info);
1962                 if (!ret && get.size == info.size) {
1963                         ret = compat_copy_entries_to_user(private->size,
1964                                                           t, uptr->entrytable);
1965                 } else if (!ret) {
1966                         duprintf("compat_get_entries: I've got %u not %u!\n",
1967                                  private->size, get.size);
1968                         ret = -EAGAIN;
1969                 }
1970                 xt_compat_flush_offsets(AF_INET6);
1971                 module_put(t->me);
1972                 xt_table_unlock(t);
1973         } else
1974                 ret = t ? PTR_ERR(t) : -ENOENT;
1975
1976         xt_compat_unlock(AF_INET6);
1977         return ret;
1978 }
1979
1980 static int do_ip6t_get_ctl(struct sock *, int, void __user *, int *);
1981
1982 static int
1983 compat_do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1984 {
1985         int ret;
1986
1987         if (!capable(CAP_NET_ADMIN))
1988                 return -EPERM;
1989
1990         switch (cmd) {
1991         case IP6T_SO_GET_INFO:
1992                 ret = get_info(sock_net(sk), user, len, 1);
1993                 break;
1994         case IP6T_SO_GET_ENTRIES:
1995                 ret = compat_get_entries(sock_net(sk), user, len);
1996                 break;
1997         default:
1998                 ret = do_ip6t_get_ctl(sk, cmd, user, len);
1999         }
2000         return ret;
2001 }
2002 #endif
2003
2004 static int
2005 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
2006 {
2007         int ret;
2008
2009         if (!capable(CAP_NET_ADMIN))
2010                 return -EPERM;
2011
2012         switch (cmd) {
2013         case IP6T_SO_SET_REPLACE:
2014                 ret = do_replace(sock_net(sk), user, len);
2015                 break;
2016
2017         case IP6T_SO_SET_ADD_COUNTERS:
2018                 ret = do_add_counters(sock_net(sk), user, len, 0);
2019                 break;
2020
2021         default:
2022                 duprintf("do_ip6t_set_ctl:  unknown request %i\n", cmd);
2023                 ret = -EINVAL;
2024         }
2025
2026         return ret;
2027 }
2028
2029 static int
2030 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2031 {
2032         int ret;
2033
2034         if (!capable(CAP_NET_ADMIN))
2035                 return -EPERM;
2036
2037         switch (cmd) {
2038         case IP6T_SO_GET_INFO:
2039                 ret = get_info(sock_net(sk), user, len, 0);
2040                 break;
2041
2042         case IP6T_SO_GET_ENTRIES:
2043                 ret = get_entries(sock_net(sk), user, len);
2044                 break;
2045
2046         case IP6T_SO_GET_REVISION_MATCH:
2047         case IP6T_SO_GET_REVISION_TARGET: {
2048                 struct xt_get_revision rev;
2049                 int target;
2050
2051                 if (*len != sizeof(rev)) {
2052                         ret = -EINVAL;
2053                         break;
2054                 }
2055                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2056                         ret = -EFAULT;
2057                         break;
2058                 }
2059                 rev.name[sizeof(rev.name)-1] = 0;
2060
2061                 if (cmd == IP6T_SO_GET_REVISION_TARGET)
2062                         target = 1;
2063                 else
2064                         target = 0;
2065
2066                 try_then_request_module(xt_find_revision(AF_INET6, rev.name,
2067                                                          rev.revision,
2068                                                          target, &ret),
2069                                         "ip6t_%s", rev.name);
2070                 break;
2071         }
2072
2073         default:
2074                 duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd);
2075                 ret = -EINVAL;
2076         }
2077
2078         return ret;
2079 }
2080
2081 struct xt_table *ip6t_register_table(struct net *net,
2082                                      const struct xt_table *table,
2083                                      const struct ip6t_replace *repl)
2084 {
2085         int ret;
2086         struct xt_table_info *newinfo;
2087         struct xt_table_info bootstrap = {0};
2088         void *loc_cpu_entry;
2089         struct xt_table *new_table;
2090
2091         newinfo = xt_alloc_table_info(repl->size);
2092         if (!newinfo) {
2093                 ret = -ENOMEM;
2094                 goto out;
2095         }
2096
2097         /* choose the copy on our node/cpu, but dont care about preemption */
2098         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2099         memcpy(loc_cpu_entry, repl->entries, repl->size);
2100
2101         ret = translate_table(net, newinfo, loc_cpu_entry, repl);
2102         if (ret != 0)
2103                 goto out_free;
2104
2105         new_table = xt_register_table(net, table, &bootstrap, newinfo);
2106         if (IS_ERR(new_table)) {
2107                 ret = PTR_ERR(new_table);
2108                 goto out_free;
2109         }
2110         return new_table;
2111
2112 out_free:
2113         xt_free_table_info(newinfo);
2114 out:
2115         return ERR_PTR(ret);
2116 }
2117
2118 void ip6t_unregister_table(struct net *net, struct xt_table *table)
2119 {
2120         struct xt_table_info *private;
2121         void *loc_cpu_entry;
2122         struct module *table_owner = table->me;
2123         struct ip6t_entry *iter;
2124
2125         private = xt_unregister_table(table);
2126
2127         /* Decrease module usage counts and free resources */
2128         loc_cpu_entry = private->entries[raw_smp_processor_id()];
2129         xt_entry_foreach(iter, loc_cpu_entry, private->size)
2130                 cleanup_entry(iter, net);
2131         if (private->number > private->initial_entries)
2132                 module_put(table_owner);
2133         xt_free_table_info(private);
2134 }
2135
2136 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2137 static inline bool
2138 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2139                      u_int8_t type, u_int8_t code,
2140                      bool invert)
2141 {
2142         return (type == test_type && code >= min_code && code <= max_code)
2143                 ^ invert;
2144 }
2145
2146 static bool
2147 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par)
2148 {
2149         const struct icmp6hdr *ic;
2150         struct icmp6hdr _icmph;
2151         const struct ip6t_icmp *icmpinfo = par->matchinfo;
2152
2153         /* Must not be a fragment. */
2154         if (par->fragoff != 0)
2155                 return false;
2156
2157         ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
2158         if (ic == NULL) {
2159                 /* We've been asked to examine this packet, and we
2160                  * can't.  Hence, no choice but to drop.
2161                  */
2162                 duprintf("Dropping evil ICMP tinygram.\n");
2163                 par->hotdrop = true;
2164                 return false;
2165         }
2166
2167         return icmp6_type_code_match(icmpinfo->type,
2168                                      icmpinfo->code[0],
2169                                      icmpinfo->code[1],
2170                                      ic->icmp6_type, ic->icmp6_code,
2171                                      !!(icmpinfo->invflags&IP6T_ICMP_INV));
2172 }
2173
2174 /* Called when user tries to insert an entry of this type. */
2175 static int icmp6_checkentry(const struct xt_mtchk_param *par)
2176 {
2177         const struct ip6t_icmp *icmpinfo = par->matchinfo;
2178
2179         /* Must specify no unknown invflags */
2180         return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0;
2181 }
2182
2183 /* The built-in targets: standard (NULL) and error. */
2184 static struct xt_target ip6t_builtin_tg[] __read_mostly = {
2185         {
2186                 .name             = XT_STANDARD_TARGET,
2187                 .targetsize       = sizeof(int),
2188                 .family           = NFPROTO_IPV6,
2189 #ifdef CONFIG_COMPAT
2190                 .compatsize       = sizeof(compat_int_t),
2191                 .compat_from_user = compat_standard_from_user,
2192                 .compat_to_user   = compat_standard_to_user,
2193 #endif
2194         },
2195         {
2196                 .name             = XT_ERROR_TARGET,
2197                 .target           = ip6t_error,
2198                 .targetsize       = XT_FUNCTION_MAXNAMELEN,
2199                 .family           = NFPROTO_IPV6,
2200         },
2201 };
2202
2203 static struct nf_sockopt_ops ip6t_sockopts = {
2204         .pf             = PF_INET6,
2205         .set_optmin     = IP6T_BASE_CTL,
2206         .set_optmax     = IP6T_SO_SET_MAX+1,
2207         .set            = do_ip6t_set_ctl,
2208 #ifdef CONFIG_COMPAT
2209         .compat_set     = compat_do_ip6t_set_ctl,
2210 #endif
2211         .get_optmin     = IP6T_BASE_CTL,
2212         .get_optmax     = IP6T_SO_GET_MAX+1,
2213         .get            = do_ip6t_get_ctl,
2214 #ifdef CONFIG_COMPAT
2215         .compat_get     = compat_do_ip6t_get_ctl,
2216 #endif
2217         .owner          = THIS_MODULE,
2218 };
2219
2220 static struct xt_match ip6t_builtin_mt[] __read_mostly = {
2221         {
2222                 .name       = "icmp6",
2223                 .match      = icmp6_match,
2224                 .matchsize  = sizeof(struct ip6t_icmp),
2225                 .checkentry = icmp6_checkentry,
2226                 .proto      = IPPROTO_ICMPV6,
2227                 .family     = NFPROTO_IPV6,
2228         },
2229 };
2230
2231 static int __net_init ip6_tables_net_init(struct net *net)
2232 {
2233         return xt_proto_init(net, NFPROTO_IPV6);
2234 }
2235
2236 static void __net_exit ip6_tables_net_exit(struct net *net)
2237 {
2238         xt_proto_fini(net, NFPROTO_IPV6);
2239 }
2240
2241 static struct pernet_operations ip6_tables_net_ops = {
2242         .init = ip6_tables_net_init,
2243         .exit = ip6_tables_net_exit,
2244 };
2245
2246 static int __init ip6_tables_init(void)
2247 {
2248         int ret;
2249
2250         ret = register_pernet_subsys(&ip6_tables_net_ops);
2251         if (ret < 0)
2252                 goto err1;
2253
2254         /* No one else will be downing sem now, so we won't sleep */
2255         ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
2256         if (ret < 0)
2257                 goto err2;
2258         ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
2259         if (ret < 0)
2260                 goto err4;
2261
2262         /* Register setsockopt */
2263         ret = nf_register_sockopt(&ip6t_sockopts);
2264         if (ret < 0)
2265                 goto err5;
2266
2267         pr_info("(C) 2000-2006 Netfilter Core Team\n");
2268         return 0;
2269
2270 err5:
2271         xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
2272 err4:
2273         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
2274 err2:
2275         unregister_pernet_subsys(&ip6_tables_net_ops);
2276 err1:
2277         return ret;
2278 }
2279
2280 static void __exit ip6_tables_fini(void)
2281 {
2282         nf_unregister_sockopt(&ip6t_sockopts);
2283
2284         xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
2285         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
2286         unregister_pernet_subsys(&ip6_tables_net_ops);
2287 }
2288
2289 /*
2290  * find the offset to specified header or the protocol number of last header
2291  * if target < 0. "last header" is transport protocol header, ESP, or
2292  * "No next header".
2293  *
2294  * If target header is found, its offset is set in *offset and return protocol
2295  * number. Otherwise, return -ENOENT or -EBADMSG.
2296  *
2297  * If the first fragment doesn't contain the final protocol header or
2298  * NEXTHDR_NONE it is considered invalid.
2299  *
2300  * Note that non-1st fragment is special case that "the protocol number
2301  * of last header" is "next header" field in Fragment header. In this case,
2302  * *offset is meaningless. If fragoff is not NULL, the fragment offset is
2303  * stored in *fragoff; if it is NULL, return -EINVAL.
2304  */
2305 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
2306                   int target, unsigned short *fragoff)
2307 {
2308         unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
2309         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
2310         unsigned int len = skb->len - start;
2311
2312         if (fragoff)
2313                 *fragoff = 0;
2314
2315         while (nexthdr != target) {
2316                 struct ipv6_opt_hdr _hdr, *hp;
2317                 unsigned int hdrlen;
2318
2319                 if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
2320                         if (target < 0)
2321                                 break;
2322                         return -ENOENT;
2323                 }
2324
2325                 hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
2326                 if (hp == NULL)
2327                         return -EBADMSG;
2328                 if (nexthdr == NEXTHDR_FRAGMENT) {
2329                         unsigned short _frag_off;
2330                         __be16 *fp;
2331                         fp = skb_header_pointer(skb,
2332                                                 start+offsetof(struct frag_hdr,
2333                                                                frag_off),
2334                                                 sizeof(_frag_off),
2335                                                 &_frag_off);
2336                         if (fp == NULL)
2337                                 return -EBADMSG;
2338
2339                         _frag_off = ntohs(*fp) & ~0x7;
2340                         if (_frag_off) {
2341                                 if (target < 0 &&
2342                                     ((!ipv6_ext_hdr(hp->nexthdr)) ||
2343                                      hp->nexthdr == NEXTHDR_NONE)) {
2344                                         if (fragoff) {
2345                                                 *fragoff = _frag_off;
2346                                                 return hp->nexthdr;
2347                                         } else {
2348                                                 return -EINVAL;
2349                                         }
2350                                 }
2351                                 return -ENOENT;
2352                         }
2353                         hdrlen = 8;
2354                 } else if (nexthdr == NEXTHDR_AUTH)
2355                         hdrlen = (hp->hdrlen + 2) << 2;
2356                 else
2357                         hdrlen = ipv6_optlen(hp);
2358
2359                 nexthdr = hp->nexthdr;
2360                 len -= hdrlen;
2361                 start += hdrlen;
2362         }
2363
2364         *offset = start;
2365         return nexthdr;
2366 }
2367
2368 EXPORT_SYMBOL(ip6t_register_table);
2369 EXPORT_SYMBOL(ip6t_unregister_table);
2370 EXPORT_SYMBOL(ip6t_do_table);
2371 EXPORT_SYMBOL(ip6t_ext_hdr);
2372 EXPORT_SYMBOL(ipv6_find_hdr);
2373
2374 module_init(ip6_tables_init);
2375 module_exit(ip6_tables_fini);