[NETFILTER]: x_tables: switch xt_match->match to bool
[linux-2.6.git] / net / ipv4 / netfilter / ip_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 #include <linux/cache.h>
12 #include <linux/capability.h>
13 #include <linux/skbuff.h>
14 #include <linux/kmod.h>
15 #include <linux/vmalloc.h>
16 #include <linux/netdevice.h>
17 #include <linux/module.h>
18 #include <linux/icmp.h>
19 #include <net/ip.h>
20 #include <net/compat.h>
21 #include <asm/uaccess.h>
22 #include <linux/mutex.h>
23 #include <linux/proc_fs.h>
24 #include <linux/err.h>
25 #include <linux/cpumask.h>
26
27 #include <linux/netfilter/x_tables.h>
28 #include <linux/netfilter_ipv4/ip_tables.h>
29
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
32 MODULE_DESCRIPTION("IPv4 packet filter");
33
34 /*#define DEBUG_IP_FIREWALL*/
35 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
36 /*#define DEBUG_IP_FIREWALL_USER*/
37
38 #ifdef DEBUG_IP_FIREWALL
39 #define dprintf(format, args...)  printk(format , ## args)
40 #else
41 #define dprintf(format, args...)
42 #endif
43
44 #ifdef DEBUG_IP_FIREWALL_USER
45 #define duprintf(format, args...) printk(format , ## args)
46 #else
47 #define duprintf(format, args...)
48 #endif
49
50 #ifdef CONFIG_NETFILTER_DEBUG
51 #define IP_NF_ASSERT(x)                                         \
52 do {                                                            \
53         if (!(x))                                               \
54                 printk("IP_NF_ASSERT: %s:%s:%u\n",              \
55                        __FUNCTION__, __FILE__, __LINE__);       \
56 } while(0)
57 #else
58 #define IP_NF_ASSERT(x)
59 #endif
60
61 #if 0
62 /* All the better to debug you with... */
63 #define static
64 #define inline
65 #endif
66
67 /*
68    We keep a set of rules for each CPU, so we can avoid write-locking
69    them in the softirq when updating the counters and therefore
70    only need to read-lock in the softirq; doing a write_lock_bh() in user
71    context stops packets coming through and allows user context to read
72    the counters or update the rules.
73
74    Hence the start of any table is given by get_table() below.  */
75
76 /* Returns whether matches rule or not. */
77 static inline int
78 ip_packet_match(const struct iphdr *ip,
79                 const char *indev,
80                 const char *outdev,
81                 const struct ipt_ip *ipinfo,
82                 int isfrag)
83 {
84         size_t i;
85         unsigned long ret;
86
87 #define FWINV(bool,invflg) ((bool) ^ !!(ipinfo->invflags & invflg))
88
89         if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
90                   IPT_INV_SRCIP)
91             || FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
92                      IPT_INV_DSTIP)) {
93                 dprintf("Source or dest mismatch.\n");
94
95                 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
96                         NIPQUAD(ip->saddr),
97                         NIPQUAD(ipinfo->smsk.s_addr),
98                         NIPQUAD(ipinfo->src.s_addr),
99                         ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
100                 dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
101                         NIPQUAD(ip->daddr),
102                         NIPQUAD(ipinfo->dmsk.s_addr),
103                         NIPQUAD(ipinfo->dst.s_addr),
104                         ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
105                 return 0;
106         }
107
108         /* Look for ifname matches; this should unroll nicely. */
109         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
110                 ret |= (((const unsigned long *)indev)[i]
111                         ^ ((const unsigned long *)ipinfo->iniface)[i])
112                         & ((const unsigned long *)ipinfo->iniface_mask)[i];
113         }
114
115         if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
116                 dprintf("VIA in mismatch (%s vs %s).%s\n",
117                         indev, ipinfo->iniface,
118                         ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
119                 return 0;
120         }
121
122         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
123                 ret |= (((const unsigned long *)outdev)[i]
124                         ^ ((const unsigned long *)ipinfo->outiface)[i])
125                         & ((const unsigned long *)ipinfo->outiface_mask)[i];
126         }
127
128         if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
129                 dprintf("VIA out mismatch (%s vs %s).%s\n",
130                         outdev, ipinfo->outiface,
131                         ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
132                 return 0;
133         }
134
135         /* Check specific protocol */
136         if (ipinfo->proto
137             && FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
138                 dprintf("Packet protocol %hi does not match %hi.%s\n",
139                         ip->protocol, ipinfo->proto,
140                         ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
141                 return 0;
142         }
143
144         /* If we have a fragment rule but the packet is not a fragment
145          * then we return zero */
146         if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
147                 dprintf("Fragment rule but not fragment.%s\n",
148                         ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
149                 return 0;
150         }
151
152         return 1;
153 }
154
155 static inline int
156 ip_checkentry(const struct ipt_ip *ip)
157 {
158         if (ip->flags & ~IPT_F_MASK) {
159                 duprintf("Unknown flag bits set: %08X\n",
160                          ip->flags & ~IPT_F_MASK);
161                 return 0;
162         }
163         if (ip->invflags & ~IPT_INV_MASK) {
164                 duprintf("Unknown invflag bits set: %08X\n",
165                          ip->invflags & ~IPT_INV_MASK);
166                 return 0;
167         }
168         return 1;
169 }
170
171 static unsigned int
172 ipt_error(struct sk_buff **pskb,
173           const struct net_device *in,
174           const struct net_device *out,
175           unsigned int hooknum,
176           const struct xt_target *target,
177           const void *targinfo)
178 {
179         if (net_ratelimit())
180                 printk("ip_tables: error: `%s'\n", (char *)targinfo);
181
182         return NF_DROP;
183 }
184
185 static inline
186 bool do_match(struct ipt_entry_match *m,
187               const struct sk_buff *skb,
188               const struct net_device *in,
189               const struct net_device *out,
190               int offset,
191               bool *hotdrop)
192 {
193         /* Stop iteration if it doesn't match */
194         if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
195                                       offset, ip_hdrlen(skb), hotdrop))
196                 return true;
197         else
198                 return false;
199 }
200
201 static inline struct ipt_entry *
202 get_entry(void *base, unsigned int offset)
203 {
204         return (struct ipt_entry *)(base + offset);
205 }
206
207 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
208 unsigned int
209 ipt_do_table(struct sk_buff **pskb,
210              unsigned int hook,
211              const struct net_device *in,
212              const struct net_device *out,
213              struct xt_table *table)
214 {
215         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
216         u_int16_t offset;
217         struct iphdr *ip;
218         u_int16_t datalen;
219         bool hotdrop = false;
220         /* Initializing verdict to NF_DROP keeps gcc happy. */
221         unsigned int verdict = NF_DROP;
222         const char *indev, *outdev;
223         void *table_base;
224         struct ipt_entry *e, *back;
225         struct xt_table_info *private;
226
227         /* Initialization */
228         ip = ip_hdr(*pskb);
229         datalen = (*pskb)->len - ip->ihl * 4;
230         indev = in ? in->name : nulldevname;
231         outdev = out ? out->name : nulldevname;
232         /* We handle fragments by dealing with the first fragment as
233          * if it was a normal packet.  All other fragments are treated
234          * normally, except that they will NEVER match rules that ask
235          * things we don't know, ie. tcp syn flag or ports).  If the
236          * rule is also a fragment-specific rule, non-fragments won't
237          * match it. */
238         offset = ntohs(ip->frag_off) & IP_OFFSET;
239
240         read_lock_bh(&table->lock);
241         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
242         private = table->private;
243         table_base = (void *)private->entries[smp_processor_id()];
244         e = get_entry(table_base, private->hook_entry[hook]);
245
246         /* For return from builtin chain */
247         back = get_entry(table_base, private->underflow[hook]);
248
249         do {
250                 IP_NF_ASSERT(e);
251                 IP_NF_ASSERT(back);
252                 if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) {
253                         struct ipt_entry_target *t;
254
255                         if (IPT_MATCH_ITERATE(e, do_match,
256                                               *pskb, in, out,
257                                               offset, &hotdrop) != 0)
258                                 goto no_match;
259
260                         ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
261
262                         t = ipt_get_target(e);
263                         IP_NF_ASSERT(t->u.kernel.target);
264                         /* Standard target? */
265                         if (!t->u.kernel.target->target) {
266                                 int v;
267
268                                 v = ((struct ipt_standard_target *)t)->verdict;
269                                 if (v < 0) {
270                                         /* Pop from stack? */
271                                         if (v != IPT_RETURN) {
272                                                 verdict = (unsigned)(-v) - 1;
273                                                 break;
274                                         }
275                                         e = back;
276                                         back = get_entry(table_base,
277                                                          back->comefrom);
278                                         continue;
279                                 }
280                                 if (table_base + v != (void *)e + e->next_offset
281                                     && !(e->ip.flags & IPT_F_GOTO)) {
282                                         /* Save old back ptr in next entry */
283                                         struct ipt_entry *next
284                                                 = (void *)e + e->next_offset;
285                                         next->comefrom
286                                                 = (void *)back - table_base;
287                                         /* set back pointer to next entry */
288                                         back = next;
289                                 }
290
291                                 e = get_entry(table_base, v);
292                         } else {
293                                 /* Targets which reenter must return
294                                    abs. verdicts */
295 #ifdef CONFIG_NETFILTER_DEBUG
296                                 ((struct ipt_entry *)table_base)->comefrom
297                                         = 0xeeeeeeec;
298 #endif
299                                 verdict = t->u.kernel.target->target(pskb,
300                                                                      in, out,
301                                                                      hook,
302                                                                      t->u.kernel.target,
303                                                                      t->data);
304
305 #ifdef CONFIG_NETFILTER_DEBUG
306                                 if (((struct ipt_entry *)table_base)->comefrom
307                                     != 0xeeeeeeec
308                                     && verdict == IPT_CONTINUE) {
309                                         printk("Target %s reentered!\n",
310                                                t->u.kernel.target->name);
311                                         verdict = NF_DROP;
312                                 }
313                                 ((struct ipt_entry *)table_base)->comefrom
314                                         = 0x57acc001;
315 #endif
316                                 /* Target might have changed stuff. */
317                                 ip = ip_hdr(*pskb);
318                                 datalen = (*pskb)->len - ip->ihl * 4;
319
320                                 if (verdict == IPT_CONTINUE)
321                                         e = (void *)e + e->next_offset;
322                                 else
323                                         /* Verdict */
324                                         break;
325                         }
326                 } else {
327
328                 no_match:
329                         e = (void *)e + e->next_offset;
330                 }
331         } while (!hotdrop);
332
333         read_unlock_bh(&table->lock);
334
335 #ifdef DEBUG_ALLOW_ALL
336         return NF_ACCEPT;
337 #else
338         if (hotdrop)
339                 return NF_DROP;
340         else return verdict;
341 #endif
342 }
343
344 /* All zeroes == unconditional rule. */
345 static inline int
346 unconditional(const struct ipt_ip *ip)
347 {
348         unsigned int i;
349
350         for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
351                 if (((__u32 *)ip)[i])
352                         return 0;
353
354         return 1;
355 }
356
357 /* Figures out from what hook each rule can be called: returns 0 if
358    there are loops.  Puts hook bitmask in comefrom. */
359 static int
360 mark_source_chains(struct xt_table_info *newinfo,
361                    unsigned int valid_hooks, void *entry0)
362 {
363         unsigned int hook;
364
365         /* No recursion; use packet counter to save back ptrs (reset
366            to 0 as we leave), and comefrom to save source hook bitmask */
367         for (hook = 0; hook < NF_IP_NUMHOOKS; hook++) {
368                 unsigned int pos = newinfo->hook_entry[hook];
369                 struct ipt_entry *e
370                         = (struct ipt_entry *)(entry0 + pos);
371
372                 if (!(valid_hooks & (1 << hook)))
373                         continue;
374
375                 /* Set initial back pointer. */
376                 e->counters.pcnt = pos;
377
378                 for (;;) {
379                         struct ipt_standard_target *t
380                                 = (void *)ipt_get_target(e);
381                         int visited = e->comefrom & (1 << hook);
382
383                         if (e->comefrom & (1 << NF_IP_NUMHOOKS)) {
384                                 printk("iptables: loop hook %u pos %u %08X.\n",
385                                        hook, pos, e->comefrom);
386                                 return 0;
387                         }
388                         e->comefrom
389                                 |= ((1 << hook) | (1 << NF_IP_NUMHOOKS));
390
391                         /* Unconditional return/END. */
392                         if ((e->target_offset == sizeof(struct ipt_entry)
393                             && (strcmp(t->target.u.user.name,
394                                        IPT_STANDARD_TARGET) == 0)
395                             && t->verdict < 0
396                             && unconditional(&e->ip)) || visited) {
397                                 unsigned int oldpos, size;
398
399                                 if (t->verdict < -NF_MAX_VERDICT - 1) {
400                                         duprintf("mark_source_chains: bad "
401                                                 "negative verdict (%i)\n",
402                                                                 t->verdict);
403                                         return 0;
404                                 }
405
406                                 /* Return: backtrack through the last
407                                    big jump. */
408                                 do {
409                                         e->comefrom ^= (1<<NF_IP_NUMHOOKS);
410 #ifdef DEBUG_IP_FIREWALL_USER
411                                         if (e->comefrom
412                                             & (1 << NF_IP_NUMHOOKS)) {
413                                                 duprintf("Back unset "
414                                                          "on hook %u "
415                                                          "rule %u\n",
416                                                          hook, pos);
417                                         }
418 #endif
419                                         oldpos = pos;
420                                         pos = e->counters.pcnt;
421                                         e->counters.pcnt = 0;
422
423                                         /* We're at the start. */
424                                         if (pos == oldpos)
425                                                 goto next;
426
427                                         e = (struct ipt_entry *)
428                                                 (entry0 + pos);
429                                 } while (oldpos == pos + e->next_offset);
430
431                                 /* Move along one */
432                                 size = e->next_offset;
433                                 e = (struct ipt_entry *)
434                                         (entry0 + pos + size);
435                                 e->counters.pcnt = pos;
436                                 pos += size;
437                         } else {
438                                 int newpos = t->verdict;
439
440                                 if (strcmp(t->target.u.user.name,
441                                            IPT_STANDARD_TARGET) == 0
442                                     && newpos >= 0) {
443                                         if (newpos > newinfo->size -
444                                                 sizeof(struct ipt_entry)) {
445                                                 duprintf("mark_source_chains: "
446                                                         "bad verdict (%i)\n",
447                                                                 newpos);
448                                                 return 0;
449                                         }
450                                         /* This a jump; chase it. */
451                                         duprintf("Jump rule %u -> %u\n",
452                                                  pos, newpos);
453                                 } else {
454                                         /* ... this is a fallthru */
455                                         newpos = pos + e->next_offset;
456                                 }
457                                 e = (struct ipt_entry *)
458                                         (entry0 + newpos);
459                                 e->counters.pcnt = pos;
460                                 pos = newpos;
461                         }
462                 }
463                 next:
464                 duprintf("Finished chain %u\n", hook);
465         }
466         return 1;
467 }
468
469 static inline int
470 cleanup_match(struct ipt_entry_match *m, unsigned int *i)
471 {
472         if (i && (*i)-- == 0)
473                 return 1;
474
475         if (m->u.kernel.match->destroy)
476                 m->u.kernel.match->destroy(m->u.kernel.match, m->data);
477         module_put(m->u.kernel.match->me);
478         return 0;
479 }
480
481 static inline int
482 check_entry(struct ipt_entry *e, const char *name)
483 {
484         struct ipt_entry_target *t;
485
486         if (!ip_checkentry(&e->ip)) {
487                 duprintf("ip_tables: ip check failed %p %s.\n", e, name);
488                 return -EINVAL;
489         }
490
491         if (e->target_offset + sizeof(struct ipt_entry_target) > e->next_offset)
492                 return -EINVAL;
493
494         t = ipt_get_target(e);
495         if (e->target_offset + t->u.target_size > e->next_offset)
496                 return -EINVAL;
497
498         return 0;
499 }
500
501 static inline int check_match(struct ipt_entry_match *m, const char *name,
502                                 const struct ipt_ip *ip, unsigned int hookmask,
503                                 unsigned int *i)
504 {
505         struct xt_match *match;
506         int ret;
507
508         match = m->u.kernel.match;
509         ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
510                              name, hookmask, ip->proto,
511                              ip->invflags & IPT_INV_PROTO);
512         if (!ret && m->u.kernel.match->checkentry
513             && !m->u.kernel.match->checkentry(name, ip, match, m->data,
514                                               hookmask)) {
515                 duprintf("ip_tables: check failed for `%s'.\n",
516                          m->u.kernel.match->name);
517                 ret = -EINVAL;
518         }
519         if (!ret)
520                 (*i)++;
521         return ret;
522 }
523
524 static inline int
525 find_check_match(struct ipt_entry_match *m,
526             const char *name,
527             const struct ipt_ip *ip,
528             unsigned int hookmask,
529             unsigned int *i)
530 {
531         struct xt_match *match;
532         int ret;
533
534         match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
535                                                    m->u.user.revision),
536                                         "ipt_%s", m->u.user.name);
537         if (IS_ERR(match) || !match) {
538                 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
539                 return match ? PTR_ERR(match) : -ENOENT;
540         }
541         m->u.kernel.match = match;
542
543         ret = check_match(m, name, ip, hookmask, i);
544         if (ret)
545                 goto err;
546
547         return 0;
548 err:
549         module_put(m->u.kernel.match->me);
550         return ret;
551 }
552
553 static inline int check_target(struct ipt_entry *e, const char *name)
554 {
555         struct ipt_entry_target *t;
556         struct xt_target *target;
557         int ret;
558
559         t = ipt_get_target(e);
560         target = t->u.kernel.target;
561         ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
562                               name, e->comefrom, e->ip.proto,
563                               e->ip.invflags & IPT_INV_PROTO);
564         if (!ret && t->u.kernel.target->checkentry
565                    && !t->u.kernel.target->checkentry(name, e, target,
566                                                       t->data, e->comefrom)) {
567                 duprintf("ip_tables: check failed for `%s'.\n",
568                          t->u.kernel.target->name);
569                 ret = -EINVAL;
570         }
571         return ret;
572 }
573
574 static inline int
575 find_check_entry(struct ipt_entry *e, const char *name, unsigned int size,
576             unsigned int *i)
577 {
578         struct ipt_entry_target *t;
579         struct xt_target *target;
580         int ret;
581         unsigned int j;
582
583         ret = check_entry(e, name);
584         if (ret)
585                 return ret;
586
587         j = 0;
588         ret = IPT_MATCH_ITERATE(e, find_check_match, name, &e->ip,
589                                                         e->comefrom, &j);
590         if (ret != 0)
591                 goto cleanup_matches;
592
593         t = ipt_get_target(e);
594         target = try_then_request_module(xt_find_target(AF_INET,
595                                                      t->u.user.name,
596                                                      t->u.user.revision),
597                                          "ipt_%s", t->u.user.name);
598         if (IS_ERR(target) || !target) {
599                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
600                 ret = target ? PTR_ERR(target) : -ENOENT;
601                 goto cleanup_matches;
602         }
603         t->u.kernel.target = target;
604
605         ret = check_target(e, name);
606         if (ret)
607                 goto err;
608
609         (*i)++;
610         return 0;
611  err:
612         module_put(t->u.kernel.target->me);
613  cleanup_matches:
614         IPT_MATCH_ITERATE(e, cleanup_match, &j);
615         return ret;
616 }
617
618 static inline int
619 check_entry_size_and_hooks(struct ipt_entry *e,
620                            struct xt_table_info *newinfo,
621                            unsigned char *base,
622                            unsigned char *limit,
623                            const unsigned int *hook_entries,
624                            const unsigned int *underflows,
625                            unsigned int *i)
626 {
627         unsigned int h;
628
629         if ((unsigned long)e % __alignof__(struct ipt_entry) != 0
630             || (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
631                 duprintf("Bad offset %p\n", e);
632                 return -EINVAL;
633         }
634
635         if (e->next_offset
636             < sizeof(struct ipt_entry) + sizeof(struct ipt_entry_target)) {
637                 duprintf("checking: element %p size %u\n",
638                          e, e->next_offset);
639                 return -EINVAL;
640         }
641
642         /* Check hooks & underflows */
643         for (h = 0; h < NF_IP_NUMHOOKS; h++) {
644                 if ((unsigned char *)e - base == hook_entries[h])
645                         newinfo->hook_entry[h] = hook_entries[h];
646                 if ((unsigned char *)e - base == underflows[h])
647                         newinfo->underflow[h] = underflows[h];
648         }
649
650         /* FIXME: underflows must be unconditional, standard verdicts
651            < 0 (not IPT_RETURN). --RR */
652
653         /* Clear counters and comefrom */
654         e->counters = ((struct xt_counters) { 0, 0 });
655         e->comefrom = 0;
656
657         (*i)++;
658         return 0;
659 }
660
661 static inline int
662 cleanup_entry(struct ipt_entry *e, unsigned int *i)
663 {
664         struct ipt_entry_target *t;
665
666         if (i && (*i)-- == 0)
667                 return 1;
668
669         /* Cleanup all matches */
670         IPT_MATCH_ITERATE(e, cleanup_match, NULL);
671         t = ipt_get_target(e);
672         if (t->u.kernel.target->destroy)
673                 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
674         module_put(t->u.kernel.target->me);
675         return 0;
676 }
677
678 /* Checks and translates the user-supplied table segment (held in
679    newinfo) */
680 static int
681 translate_table(const char *name,
682                 unsigned int valid_hooks,
683                 struct xt_table_info *newinfo,
684                 void *entry0,
685                 unsigned int size,
686                 unsigned int number,
687                 const unsigned int *hook_entries,
688                 const unsigned int *underflows)
689 {
690         unsigned int i;
691         int ret;
692
693         newinfo->size = size;
694         newinfo->number = number;
695
696         /* Init all hooks to impossible value. */
697         for (i = 0; i < NF_IP_NUMHOOKS; i++) {
698                 newinfo->hook_entry[i] = 0xFFFFFFFF;
699                 newinfo->underflow[i] = 0xFFFFFFFF;
700         }
701
702         duprintf("translate_table: size %u\n", newinfo->size);
703         i = 0;
704         /* Walk through entries, checking offsets. */
705         ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
706                                 check_entry_size_and_hooks,
707                                 newinfo,
708                                 entry0,
709                                 entry0 + size,
710                                 hook_entries, underflows, &i);
711         if (ret != 0)
712                 return ret;
713
714         if (i != number) {
715                 duprintf("translate_table: %u not %u entries\n",
716                          i, number);
717                 return -EINVAL;
718         }
719
720         /* Check hooks all assigned */
721         for (i = 0; i < NF_IP_NUMHOOKS; i++) {
722                 /* Only hooks which are valid */
723                 if (!(valid_hooks & (1 << i)))
724                         continue;
725                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
726                         duprintf("Invalid hook entry %u %u\n",
727                                  i, hook_entries[i]);
728                         return -EINVAL;
729                 }
730                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
731                         duprintf("Invalid underflow %u %u\n",
732                                  i, underflows[i]);
733                         return -EINVAL;
734                 }
735         }
736
737         if (!mark_source_chains(newinfo, valid_hooks, entry0))
738                 return -ELOOP;
739
740         /* Finally, each sanity check must pass */
741         i = 0;
742         ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
743                                 find_check_entry, name, size, &i);
744
745         if (ret != 0) {
746                 IPT_ENTRY_ITERATE(entry0, newinfo->size,
747                                 cleanup_entry, &i);
748                 return ret;
749         }
750
751         /* And one copy for every other CPU */
752         for_each_possible_cpu(i) {
753                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
754                         memcpy(newinfo->entries[i], entry0, newinfo->size);
755         }
756
757         return ret;
758 }
759
760 /* Gets counters. */
761 static inline int
762 add_entry_to_counter(const struct ipt_entry *e,
763                      struct xt_counters total[],
764                      unsigned int *i)
765 {
766         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
767
768         (*i)++;
769         return 0;
770 }
771
772 static inline int
773 set_entry_to_counter(const struct ipt_entry *e,
774                      struct ipt_counters total[],
775                      unsigned int *i)
776 {
777         SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
778
779         (*i)++;
780         return 0;
781 }
782
783 static void
784 get_counters(const struct xt_table_info *t,
785              struct xt_counters counters[])
786 {
787         unsigned int cpu;
788         unsigned int i;
789         unsigned int curcpu;
790
791         /* Instead of clearing (by a previous call to memset())
792          * the counters and using adds, we set the counters
793          * with data used by 'current' CPU
794          * We dont care about preemption here.
795          */
796         curcpu = raw_smp_processor_id();
797
798         i = 0;
799         IPT_ENTRY_ITERATE(t->entries[curcpu],
800                           t->size,
801                           set_entry_to_counter,
802                           counters,
803                           &i);
804
805         for_each_possible_cpu(cpu) {
806                 if (cpu == curcpu)
807                         continue;
808                 i = 0;
809                 IPT_ENTRY_ITERATE(t->entries[cpu],
810                                   t->size,
811                                   add_entry_to_counter,
812                                   counters,
813                                   &i);
814         }
815 }
816
817 static inline struct xt_counters * alloc_counters(struct xt_table *table)
818 {
819         unsigned int countersize;
820         struct xt_counters *counters;
821         struct xt_table_info *private = table->private;
822
823         /* We need atomic snapshot of counters: rest doesn't change
824            (other than comefrom, which userspace doesn't care
825            about). */
826         countersize = sizeof(struct xt_counters) * private->number;
827         counters = vmalloc_node(countersize, numa_node_id());
828
829         if (counters == NULL)
830                 return ERR_PTR(-ENOMEM);
831
832         /* First, sum counters... */
833         write_lock_bh(&table->lock);
834         get_counters(private, counters);
835         write_unlock_bh(&table->lock);
836
837         return counters;
838 }
839
840 static int
841 copy_entries_to_user(unsigned int total_size,
842                      struct xt_table *table,
843                      void __user *userptr)
844 {
845         unsigned int off, num;
846         struct ipt_entry *e;
847         struct xt_counters *counters;
848         struct xt_table_info *private = table->private;
849         int ret = 0;
850         void *loc_cpu_entry;
851
852         counters = alloc_counters(table);
853         if (IS_ERR(counters))
854                 return PTR_ERR(counters);
855
856         /* choose the copy that is on our node/cpu, ...
857          * This choice is lazy (because current thread is
858          * allowed to migrate to another cpu)
859          */
860         loc_cpu_entry = private->entries[raw_smp_processor_id()];
861         /* ... then copy entire thing ... */
862         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
863                 ret = -EFAULT;
864                 goto free_counters;
865         }
866
867         /* FIXME: use iterator macros --RR */
868         /* ... then go back and fix counters and names */
869         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
870                 unsigned int i;
871                 struct ipt_entry_match *m;
872                 struct ipt_entry_target *t;
873
874                 e = (struct ipt_entry *)(loc_cpu_entry + off);
875                 if (copy_to_user(userptr + off
876                                  + offsetof(struct ipt_entry, counters),
877                                  &counters[num],
878                                  sizeof(counters[num])) != 0) {
879                         ret = -EFAULT;
880                         goto free_counters;
881                 }
882
883                 for (i = sizeof(struct ipt_entry);
884                      i < e->target_offset;
885                      i += m->u.match_size) {
886                         m = (void *)e + i;
887
888                         if (copy_to_user(userptr + off + i
889                                          + offsetof(struct ipt_entry_match,
890                                                     u.user.name),
891                                          m->u.kernel.match->name,
892                                          strlen(m->u.kernel.match->name)+1)
893                             != 0) {
894                                 ret = -EFAULT;
895                                 goto free_counters;
896                         }
897                 }
898
899                 t = ipt_get_target(e);
900                 if (copy_to_user(userptr + off + e->target_offset
901                                  + offsetof(struct ipt_entry_target,
902                                             u.user.name),
903                                  t->u.kernel.target->name,
904                                  strlen(t->u.kernel.target->name)+1) != 0) {
905                         ret = -EFAULT;
906                         goto free_counters;
907                 }
908         }
909
910  free_counters:
911         vfree(counters);
912         return ret;
913 }
914
915 #ifdef CONFIG_COMPAT
916 struct compat_delta {
917         struct compat_delta *next;
918         unsigned int offset;
919         short delta;
920 };
921
922 static struct compat_delta *compat_offsets = NULL;
923
924 static int compat_add_offset(unsigned int offset, short delta)
925 {
926         struct compat_delta *tmp;
927
928         tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
929         if (!tmp)
930                 return -ENOMEM;
931         tmp->offset = offset;
932         tmp->delta = delta;
933         if (compat_offsets) {
934                 tmp->next = compat_offsets->next;
935                 compat_offsets->next = tmp;
936         } else {
937                 compat_offsets = tmp;
938                 tmp->next = NULL;
939         }
940         return 0;
941 }
942
943 static void compat_flush_offsets(void)
944 {
945         struct compat_delta *tmp, *next;
946
947         if (compat_offsets) {
948                 for(tmp = compat_offsets; tmp; tmp = next) {
949                         next = tmp->next;
950                         kfree(tmp);
951                 }
952                 compat_offsets = NULL;
953         }
954 }
955
956 static short compat_calc_jump(unsigned int offset)
957 {
958         struct compat_delta *tmp;
959         short delta;
960
961         for(tmp = compat_offsets, delta = 0; tmp; tmp = tmp->next)
962                 if (tmp->offset < offset)
963                         delta += tmp->delta;
964         return delta;
965 }
966
967 static void compat_standard_from_user(void *dst, void *src)
968 {
969         int v = *(compat_int_t *)src;
970
971         if (v > 0)
972                 v += compat_calc_jump(v);
973         memcpy(dst, &v, sizeof(v));
974 }
975
976 static int compat_standard_to_user(void __user *dst, void *src)
977 {
978         compat_int_t cv = *(int *)src;
979
980         if (cv > 0)
981                 cv -= compat_calc_jump(cv);
982         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
983 }
984
985 static inline int
986 compat_calc_match(struct ipt_entry_match *m, int * size)
987 {
988         *size += xt_compat_match_offset(m->u.kernel.match);
989         return 0;
990 }
991
992 static int compat_calc_entry(struct ipt_entry *e, struct xt_table_info *info,
993                 void *base, struct xt_table_info *newinfo)
994 {
995         struct ipt_entry_target *t;
996         unsigned int entry_offset;
997         int off, i, ret;
998
999         off = 0;
1000         entry_offset = (void *)e - base;
1001         IPT_MATCH_ITERATE(e, compat_calc_match, &off);
1002         t = ipt_get_target(e);
1003         off += xt_compat_target_offset(t->u.kernel.target);
1004         newinfo->size -= off;
1005         ret = compat_add_offset(entry_offset, off);
1006         if (ret)
1007                 return ret;
1008
1009         for (i = 0; i< NF_IP_NUMHOOKS; i++) {
1010                 if (info->hook_entry[i] && (e < (struct ipt_entry *)
1011                                 (base + info->hook_entry[i])))
1012                         newinfo->hook_entry[i] -= off;
1013                 if (info->underflow[i] && (e < (struct ipt_entry *)
1014                                 (base + info->underflow[i])))
1015                         newinfo->underflow[i] -= off;
1016         }
1017         return 0;
1018 }
1019
1020 static int compat_table_info(struct xt_table_info *info,
1021                 struct xt_table_info *newinfo)
1022 {
1023         void *loc_cpu_entry;
1024         int i;
1025
1026         if (!newinfo || !info)
1027                 return -EINVAL;
1028
1029         memset(newinfo, 0, sizeof(struct xt_table_info));
1030         newinfo->size = info->size;
1031         newinfo->number = info->number;
1032         for (i = 0; i < NF_IP_NUMHOOKS; i++) {
1033                 newinfo->hook_entry[i] = info->hook_entry[i];
1034                 newinfo->underflow[i] = info->underflow[i];
1035         }
1036         loc_cpu_entry = info->entries[raw_smp_processor_id()];
1037         return IPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
1038                         compat_calc_entry, info, loc_cpu_entry, newinfo);
1039 }
1040 #endif
1041
1042 static int get_info(void __user *user, int *len, int compat)
1043 {
1044         char name[IPT_TABLE_MAXNAMELEN];
1045         struct xt_table *t;
1046         int ret;
1047
1048         if (*len != sizeof(struct ipt_getinfo)) {
1049                 duprintf("length %u != %u\n", *len,
1050                         (unsigned int)sizeof(struct ipt_getinfo));
1051                 return -EINVAL;
1052         }
1053
1054         if (copy_from_user(name, user, sizeof(name)) != 0)
1055                 return -EFAULT;
1056
1057         name[IPT_TABLE_MAXNAMELEN-1] = '\0';
1058 #ifdef CONFIG_COMPAT
1059         if (compat)
1060                 xt_compat_lock(AF_INET);
1061 #endif
1062         t = try_then_request_module(xt_find_table_lock(AF_INET, name),
1063                         "iptable_%s", name);
1064         if (t && !IS_ERR(t)) {
1065                 struct ipt_getinfo info;
1066                 struct xt_table_info *private = t->private;
1067
1068 #ifdef CONFIG_COMPAT
1069                 if (compat) {
1070                         struct xt_table_info tmp;
1071                         ret = compat_table_info(private, &tmp);
1072                         compat_flush_offsets();
1073                         private =  &tmp;
1074                 }
1075 #endif
1076                 info.valid_hooks = t->valid_hooks;
1077                 memcpy(info.hook_entry, private->hook_entry,
1078                                 sizeof(info.hook_entry));
1079                 memcpy(info.underflow, private->underflow,
1080                                 sizeof(info.underflow));
1081                 info.num_entries = private->number;
1082                 info.size = private->size;
1083                 strcpy(info.name, name);
1084
1085                 if (copy_to_user(user, &info, *len) != 0)
1086                         ret = -EFAULT;
1087                 else
1088                         ret = 0;
1089
1090                 xt_table_unlock(t);
1091                 module_put(t->me);
1092         } else
1093                 ret = t ? PTR_ERR(t) : -ENOENT;
1094 #ifdef CONFIG_COMPAT
1095         if (compat)
1096                 xt_compat_unlock(AF_INET);
1097 #endif
1098         return ret;
1099 }
1100
1101 static int
1102 get_entries(struct ipt_get_entries __user *uptr, int *len)
1103 {
1104         int ret;
1105         struct ipt_get_entries get;
1106         struct xt_table *t;
1107
1108         if (*len < sizeof(get)) {
1109                 duprintf("get_entries: %u < %d\n", *len,
1110                                 (unsigned int)sizeof(get));
1111                 return -EINVAL;
1112         }
1113         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1114                 return -EFAULT;
1115         if (*len != sizeof(struct ipt_get_entries) + get.size) {
1116                 duprintf("get_entries: %u != %u\n", *len,
1117                                 (unsigned int)(sizeof(struct ipt_get_entries) +
1118                                 get.size));
1119                 return -EINVAL;
1120         }
1121
1122         t = xt_find_table_lock(AF_INET, get.name);
1123         if (t && !IS_ERR(t)) {
1124                 struct xt_table_info *private = t->private;
1125                 duprintf("t->private->number = %u\n",
1126                          private->number);
1127                 if (get.size == private->size)
1128                         ret = copy_entries_to_user(private->size,
1129                                                    t, uptr->entrytable);
1130                 else {
1131                         duprintf("get_entries: I've got %u not %u!\n",
1132                                  private->size,
1133                                  get.size);
1134                         ret = -EINVAL;
1135                 }
1136                 module_put(t->me);
1137                 xt_table_unlock(t);
1138         } else
1139                 ret = t ? PTR_ERR(t) : -ENOENT;
1140
1141         return ret;
1142 }
1143
1144 static int
1145 __do_replace(const char *name, unsigned int valid_hooks,
1146                 struct xt_table_info *newinfo, unsigned int num_counters,
1147                 void __user *counters_ptr)
1148 {
1149         int ret;
1150         struct xt_table *t;
1151         struct xt_table_info *oldinfo;
1152         struct xt_counters *counters;
1153         void *loc_cpu_old_entry;
1154
1155         ret = 0;
1156         counters = vmalloc(num_counters * sizeof(struct xt_counters));
1157         if (!counters) {
1158                 ret = -ENOMEM;
1159                 goto out;
1160         }
1161
1162         t = try_then_request_module(xt_find_table_lock(AF_INET, name),
1163                                     "iptable_%s", name);
1164         if (!t || IS_ERR(t)) {
1165                 ret = t ? PTR_ERR(t) : -ENOENT;
1166                 goto free_newinfo_counters_untrans;
1167         }
1168
1169         /* You lied! */
1170         if (valid_hooks != t->valid_hooks) {
1171                 duprintf("Valid hook crap: %08X vs %08X\n",
1172                          valid_hooks, t->valid_hooks);
1173                 ret = -EINVAL;
1174                 goto put_module;
1175         }
1176
1177         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1178         if (!oldinfo)
1179                 goto put_module;
1180
1181         /* Update module usage count based on number of rules */
1182         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1183                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1184         if ((oldinfo->number > oldinfo->initial_entries) ||
1185             (newinfo->number <= oldinfo->initial_entries))
1186                 module_put(t->me);
1187         if ((oldinfo->number > oldinfo->initial_entries) &&
1188             (newinfo->number <= oldinfo->initial_entries))
1189                 module_put(t->me);
1190
1191         /* Get the old counters. */
1192         get_counters(oldinfo, counters);
1193         /* Decrease module usage counts and free resource */
1194         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1195         IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
1196         xt_free_table_info(oldinfo);
1197         if (copy_to_user(counters_ptr, counters,
1198                          sizeof(struct xt_counters) * num_counters) != 0)
1199                 ret = -EFAULT;
1200         vfree(counters);
1201         xt_table_unlock(t);
1202         return ret;
1203
1204  put_module:
1205         module_put(t->me);
1206         xt_table_unlock(t);
1207  free_newinfo_counters_untrans:
1208         vfree(counters);
1209  out:
1210         return ret;
1211 }
1212
1213 static int
1214 do_replace(void __user *user, unsigned int len)
1215 {
1216         int ret;
1217         struct ipt_replace tmp;
1218         struct xt_table_info *newinfo;
1219         void *loc_cpu_entry;
1220
1221         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1222                 return -EFAULT;
1223
1224         /* Hack: Causes ipchains to give correct error msg --RR */
1225         if (len != sizeof(tmp) + tmp.size)
1226                 return -ENOPROTOOPT;
1227
1228         /* overflow check */
1229         if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
1230                         SMP_CACHE_BYTES)
1231                 return -ENOMEM;
1232         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1233                 return -ENOMEM;
1234
1235         newinfo = xt_alloc_table_info(tmp.size);
1236         if (!newinfo)
1237                 return -ENOMEM;
1238
1239         /* choose the copy that is our node/cpu */
1240         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1241         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1242                            tmp.size) != 0) {
1243                 ret = -EFAULT;
1244                 goto free_newinfo;
1245         }
1246
1247         ret = translate_table(tmp.name, tmp.valid_hooks,
1248                               newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1249                               tmp.hook_entry, tmp.underflow);
1250         if (ret != 0)
1251                 goto free_newinfo;
1252
1253         duprintf("ip_tables: Translated table\n");
1254
1255         ret = __do_replace(tmp.name, tmp.valid_hooks,
1256                               newinfo, tmp.num_counters,
1257                               tmp.counters);
1258         if (ret)
1259                 goto free_newinfo_untrans;
1260         return 0;
1261
1262  free_newinfo_untrans:
1263         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
1264  free_newinfo:
1265         xt_free_table_info(newinfo);
1266         return ret;
1267 }
1268
1269 /* We're lazy, and add to the first CPU; overflow works its fey magic
1270  * and everything is OK. */
1271 static inline int
1272 add_counter_to_entry(struct ipt_entry *e,
1273                      const struct xt_counters addme[],
1274                      unsigned int *i)
1275 {
1276 #if 0
1277         duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
1278                  *i,
1279                  (long unsigned int)e->counters.pcnt,
1280                  (long unsigned int)e->counters.bcnt,
1281                  (long unsigned int)addme[*i].pcnt,
1282                  (long unsigned int)addme[*i].bcnt);
1283 #endif
1284
1285         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1286
1287         (*i)++;
1288         return 0;
1289 }
1290
1291 static int
1292 do_add_counters(void __user *user, unsigned int len, int compat)
1293 {
1294         unsigned int i;
1295         struct xt_counters_info tmp;
1296         struct xt_counters *paddc;
1297         unsigned int num_counters;
1298         char *name;
1299         int size;
1300         void *ptmp;
1301         struct xt_table *t;
1302         struct xt_table_info *private;
1303         int ret = 0;
1304         void *loc_cpu_entry;
1305 #ifdef CONFIG_COMPAT
1306         struct compat_xt_counters_info compat_tmp;
1307
1308         if (compat) {
1309                 ptmp = &compat_tmp;
1310                 size = sizeof(struct compat_xt_counters_info);
1311         } else
1312 #endif
1313         {
1314                 ptmp = &tmp;
1315                 size = sizeof(struct xt_counters_info);
1316         }
1317
1318         if (copy_from_user(ptmp, user, size) != 0)
1319                 return -EFAULT;
1320
1321 #ifdef CONFIG_COMPAT
1322         if (compat) {
1323                 num_counters = compat_tmp.num_counters;
1324                 name = compat_tmp.name;
1325         } else
1326 #endif
1327         {
1328                 num_counters = tmp.num_counters;
1329                 name = tmp.name;
1330         }
1331
1332         if (len != size + num_counters * sizeof(struct xt_counters))
1333                 return -EINVAL;
1334
1335         paddc = vmalloc_node(len - size, numa_node_id());
1336         if (!paddc)
1337                 return -ENOMEM;
1338
1339         if (copy_from_user(paddc, user + size, len - size) != 0) {
1340                 ret = -EFAULT;
1341                 goto free;
1342         }
1343
1344         t = xt_find_table_lock(AF_INET, name);
1345         if (!t || IS_ERR(t)) {
1346                 ret = t ? PTR_ERR(t) : -ENOENT;
1347                 goto free;
1348         }
1349
1350         write_lock_bh(&t->lock);
1351         private = t->private;
1352         if (private->number != num_counters) {
1353                 ret = -EINVAL;
1354                 goto unlock_up_free;
1355         }
1356
1357         i = 0;
1358         /* Choose the copy that is on our node */
1359         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1360         IPT_ENTRY_ITERATE(loc_cpu_entry,
1361                           private->size,
1362                           add_counter_to_entry,
1363                           paddc,
1364                           &i);
1365  unlock_up_free:
1366         write_unlock_bh(&t->lock);
1367         xt_table_unlock(t);
1368         module_put(t->me);
1369  free:
1370         vfree(paddc);
1371
1372         return ret;
1373 }
1374
1375 #ifdef CONFIG_COMPAT
1376 struct compat_ipt_replace {
1377         char                    name[IPT_TABLE_MAXNAMELEN];
1378         u32                     valid_hooks;
1379         u32                     num_entries;
1380         u32                     size;
1381         u32                     hook_entry[NF_IP_NUMHOOKS];
1382         u32                     underflow[NF_IP_NUMHOOKS];
1383         u32                     num_counters;
1384         compat_uptr_t           counters;       /* struct ipt_counters * */
1385         struct compat_ipt_entry entries[0];
1386 };
1387
1388 static inline int compat_copy_match_to_user(struct ipt_entry_match *m,
1389                 void __user **dstptr, compat_uint_t *size)
1390 {
1391         return xt_compat_match_to_user(m, dstptr, size);
1392 }
1393
1394 static int compat_copy_entry_to_user(struct ipt_entry *e,
1395                 void __user **dstptr, compat_uint_t *size)
1396 {
1397         struct ipt_entry_target *t;
1398         struct compat_ipt_entry __user *ce;
1399         u_int16_t target_offset, next_offset;
1400         compat_uint_t origsize;
1401         int ret;
1402
1403         ret = -EFAULT;
1404         origsize = *size;
1405         ce = (struct compat_ipt_entry __user *)*dstptr;
1406         if (copy_to_user(ce, e, sizeof(struct ipt_entry)))
1407                 goto out;
1408
1409         *dstptr += sizeof(struct compat_ipt_entry);
1410         ret = IPT_MATCH_ITERATE(e, compat_copy_match_to_user, dstptr, size);
1411         target_offset = e->target_offset - (origsize - *size);
1412         if (ret)
1413                 goto out;
1414         t = ipt_get_target(e);
1415         ret = xt_compat_target_to_user(t, dstptr, size);
1416         if (ret)
1417                 goto out;
1418         ret = -EFAULT;
1419         next_offset = e->next_offset - (origsize - *size);
1420         if (put_user(target_offset, &ce->target_offset))
1421                 goto out;
1422         if (put_user(next_offset, &ce->next_offset))
1423                 goto out;
1424         return 0;
1425 out:
1426         return ret;
1427 }
1428
1429 static inline int
1430 compat_find_calc_match(struct ipt_entry_match *m,
1431             const char *name,
1432             const struct ipt_ip *ip,
1433             unsigned int hookmask,
1434             int *size, int *i)
1435 {
1436         struct xt_match *match;
1437
1438         match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
1439                                                    m->u.user.revision),
1440                                         "ipt_%s", m->u.user.name);
1441         if (IS_ERR(match) || !match) {
1442                 duprintf("compat_check_calc_match: `%s' not found\n",
1443                                 m->u.user.name);
1444                 return match ? PTR_ERR(match) : -ENOENT;
1445         }
1446         m->u.kernel.match = match;
1447         *size += xt_compat_match_offset(match);
1448
1449         (*i)++;
1450         return 0;
1451 }
1452
1453 static inline int
1454 compat_release_match(struct ipt_entry_match *m, unsigned int *i)
1455 {
1456         if (i && (*i)-- == 0)
1457                 return 1;
1458
1459         module_put(m->u.kernel.match->me);
1460         return 0;
1461 }
1462
1463 static inline int
1464 compat_release_entry(struct ipt_entry *e, unsigned int *i)
1465 {
1466         struct ipt_entry_target *t;
1467
1468         if (i && (*i)-- == 0)
1469                 return 1;
1470
1471         /* Cleanup all matches */
1472         IPT_MATCH_ITERATE(e, compat_release_match, NULL);
1473         t = ipt_get_target(e);
1474         module_put(t->u.kernel.target->me);
1475         return 0;
1476 }
1477
1478 static inline int
1479 check_compat_entry_size_and_hooks(struct ipt_entry *e,
1480                            struct xt_table_info *newinfo,
1481                            unsigned int *size,
1482                            unsigned char *base,
1483                            unsigned char *limit,
1484                            unsigned int *hook_entries,
1485                            unsigned int *underflows,
1486                            unsigned int *i,
1487                            const char *name)
1488 {
1489         struct ipt_entry_target *t;
1490         struct xt_target *target;
1491         unsigned int entry_offset;
1492         int ret, off, h, j;
1493
1494         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1495         if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0
1496             || (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
1497                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1498                 return -EINVAL;
1499         }
1500
1501         if (e->next_offset < sizeof(struct compat_ipt_entry) +
1502                         sizeof(struct compat_xt_entry_target)) {
1503                 duprintf("checking: element %p size %u\n",
1504                          e, e->next_offset);
1505                 return -EINVAL;
1506         }
1507
1508         ret = check_entry(e, name);
1509         if (ret)
1510                 return ret;
1511
1512         off = 0;
1513         entry_offset = (void *)e - (void *)base;
1514         j = 0;
1515         ret = IPT_MATCH_ITERATE(e, compat_find_calc_match, name, &e->ip,
1516                         e->comefrom, &off, &j);
1517         if (ret != 0)
1518                 goto release_matches;
1519
1520         t = ipt_get_target(e);
1521         target = try_then_request_module(xt_find_target(AF_INET,
1522                                                      t->u.user.name,
1523                                                      t->u.user.revision),
1524                                          "ipt_%s", t->u.user.name);
1525         if (IS_ERR(target) || !target) {
1526                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1527                                                         t->u.user.name);
1528                 ret = target ? PTR_ERR(target) : -ENOENT;
1529                 goto release_matches;
1530         }
1531         t->u.kernel.target = target;
1532
1533         off += xt_compat_target_offset(target);
1534         *size += off;
1535         ret = compat_add_offset(entry_offset, off);
1536         if (ret)
1537                 goto out;
1538
1539         /* Check hooks & underflows */
1540         for (h = 0; h < NF_IP_NUMHOOKS; h++) {
1541                 if ((unsigned char *)e - base == hook_entries[h])
1542                         newinfo->hook_entry[h] = hook_entries[h];
1543                 if ((unsigned char *)e - base == underflows[h])
1544                         newinfo->underflow[h] = underflows[h];
1545         }
1546
1547         /* Clear counters and comefrom */
1548         e->counters = ((struct ipt_counters) { 0, 0 });
1549         e->comefrom = 0;
1550
1551         (*i)++;
1552         return 0;
1553
1554 out:
1555         module_put(t->u.kernel.target->me);
1556 release_matches:
1557         IPT_MATCH_ITERATE(e, compat_release_match, &j);
1558         return ret;
1559 }
1560
1561 static inline int compat_copy_match_from_user(struct ipt_entry_match *m,
1562         void **dstptr, compat_uint_t *size, const char *name,
1563         const struct ipt_ip *ip, unsigned int hookmask)
1564 {
1565         xt_compat_match_from_user(m, dstptr, size);
1566         return 0;
1567 }
1568
1569 static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
1570         unsigned int *size, const char *name,
1571         struct xt_table_info *newinfo, unsigned char *base)
1572 {
1573         struct ipt_entry_target *t;
1574         struct xt_target *target;
1575         struct ipt_entry *de;
1576         unsigned int origsize;
1577         int ret, h;
1578
1579         ret = 0;
1580         origsize = *size;
1581         de = (struct ipt_entry *)*dstptr;
1582         memcpy(de, e, sizeof(struct ipt_entry));
1583
1584         *dstptr += sizeof(struct compat_ipt_entry);
1585         ret = IPT_MATCH_ITERATE(e, compat_copy_match_from_user, dstptr, size,
1586                         name, &de->ip, de->comefrom);
1587         if (ret)
1588                 return ret;
1589         de->target_offset = e->target_offset - (origsize - *size);
1590         t = ipt_get_target(e);
1591         target = t->u.kernel.target;
1592         xt_compat_target_from_user(t, dstptr, size);
1593
1594         de->next_offset = e->next_offset - (origsize - *size);
1595         for (h = 0; h < NF_IP_NUMHOOKS; h++) {
1596                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1597                         newinfo->hook_entry[h] -= origsize - *size;
1598                 if ((unsigned char *)de - base < newinfo->underflow[h])
1599                         newinfo->underflow[h] -= origsize - *size;
1600         }
1601         return ret;
1602 }
1603
1604 static inline int compat_check_entry(struct ipt_entry *e, const char *name,
1605                                                 unsigned int *i)
1606 {
1607         int j, ret;
1608
1609         j = 0;
1610         ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom, &j);
1611         if (ret)
1612                 goto cleanup_matches;
1613
1614         ret = check_target(e, name);
1615         if (ret)
1616                 goto cleanup_matches;
1617
1618         (*i)++;
1619         return 0;
1620
1621  cleanup_matches:
1622         IPT_MATCH_ITERATE(e, cleanup_match, &j);
1623         return ret;
1624 }
1625
1626 static int
1627 translate_compat_table(const char *name,
1628                 unsigned int valid_hooks,
1629                 struct xt_table_info **pinfo,
1630                 void **pentry0,
1631                 unsigned int total_size,
1632                 unsigned int number,
1633                 unsigned int *hook_entries,
1634                 unsigned int *underflows)
1635 {
1636         unsigned int i, j;
1637         struct xt_table_info *newinfo, *info;
1638         void *pos, *entry0, *entry1;
1639         unsigned int size;
1640         int ret;
1641
1642         info = *pinfo;
1643         entry0 = *pentry0;
1644         size = total_size;
1645         info->number = number;
1646
1647         /* Init all hooks to impossible value. */
1648         for (i = 0; i < NF_IP_NUMHOOKS; i++) {
1649                 info->hook_entry[i] = 0xFFFFFFFF;
1650                 info->underflow[i] = 0xFFFFFFFF;
1651         }
1652
1653         duprintf("translate_compat_table: size %u\n", info->size);
1654         j = 0;
1655         xt_compat_lock(AF_INET);
1656         /* Walk through entries, checking offsets. */
1657         ret = IPT_ENTRY_ITERATE(entry0, total_size,
1658                                 check_compat_entry_size_and_hooks,
1659                                 info, &size, entry0,
1660                                 entry0 + total_size,
1661                                 hook_entries, underflows, &j, name);
1662         if (ret != 0)
1663                 goto out_unlock;
1664
1665         ret = -EINVAL;
1666         if (j != number) {
1667                 duprintf("translate_compat_table: %u not %u entries\n",
1668                          j, number);
1669                 goto out_unlock;
1670         }
1671
1672         /* Check hooks all assigned */
1673         for (i = 0; i < NF_IP_NUMHOOKS; i++) {
1674                 /* Only hooks which are valid */
1675                 if (!(valid_hooks & (1 << i)))
1676                         continue;
1677                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1678                         duprintf("Invalid hook entry %u %u\n",
1679                                  i, hook_entries[i]);
1680                         goto out_unlock;
1681                 }
1682                 if (info->underflow[i] == 0xFFFFFFFF) {
1683                         duprintf("Invalid underflow %u %u\n",
1684                                  i, underflows[i]);
1685                         goto out_unlock;
1686                 }
1687         }
1688
1689         ret = -ENOMEM;
1690         newinfo = xt_alloc_table_info(size);
1691         if (!newinfo)
1692                 goto out_unlock;
1693
1694         newinfo->number = number;
1695         for (i = 0; i < NF_IP_NUMHOOKS; i++) {
1696                 newinfo->hook_entry[i] = info->hook_entry[i];
1697                 newinfo->underflow[i] = info->underflow[i];
1698         }
1699         entry1 = newinfo->entries[raw_smp_processor_id()];
1700         pos = entry1;
1701         size =  total_size;
1702         ret = IPT_ENTRY_ITERATE(entry0, total_size,
1703                         compat_copy_entry_from_user, &pos, &size,
1704                         name, newinfo, entry1);
1705         compat_flush_offsets();
1706         xt_compat_unlock(AF_INET);
1707         if (ret)
1708                 goto free_newinfo;
1709
1710         ret = -ELOOP;
1711         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1712                 goto free_newinfo;
1713
1714         i = 0;
1715         ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1716                                                                 name, &i);
1717         if (ret) {
1718                 j -= i;
1719                 IPT_ENTRY_ITERATE_CONTINUE(entry1, newinfo->size, i,
1720                                                 compat_release_entry, &j);
1721                 IPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1722                 xt_free_table_info(newinfo);
1723                 return ret;
1724         }
1725
1726         /* And one copy for every other CPU */
1727         for_each_possible_cpu(i)
1728                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1729                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1730
1731         *pinfo = newinfo;
1732         *pentry0 = entry1;
1733         xt_free_table_info(info);
1734         return 0;
1735
1736 free_newinfo:
1737         xt_free_table_info(newinfo);
1738 out:
1739         IPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1740         return ret;
1741 out_unlock:
1742         compat_flush_offsets();
1743         xt_compat_unlock(AF_INET);
1744         goto out;
1745 }
1746
1747 static int
1748 compat_do_replace(void __user *user, unsigned int len)
1749 {
1750         int ret;
1751         struct compat_ipt_replace tmp;
1752         struct xt_table_info *newinfo;
1753         void *loc_cpu_entry;
1754
1755         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1756                 return -EFAULT;
1757
1758         /* Hack: Causes ipchains to give correct error msg --RR */
1759         if (len != sizeof(tmp) + tmp.size)
1760                 return -ENOPROTOOPT;
1761
1762         /* overflow check */
1763         if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
1764                         SMP_CACHE_BYTES)
1765                 return -ENOMEM;
1766         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1767                 return -ENOMEM;
1768
1769         newinfo = xt_alloc_table_info(tmp.size);
1770         if (!newinfo)
1771                 return -ENOMEM;
1772
1773         /* choose the copy that is our node/cpu */
1774         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1775         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1776                            tmp.size) != 0) {
1777                 ret = -EFAULT;
1778                 goto free_newinfo;
1779         }
1780
1781         ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1782                               &newinfo, &loc_cpu_entry, tmp.size,
1783                               tmp.num_entries, tmp.hook_entry, tmp.underflow);
1784         if (ret != 0)
1785                 goto free_newinfo;
1786
1787         duprintf("compat_do_replace: Translated table\n");
1788
1789         ret = __do_replace(tmp.name, tmp.valid_hooks,
1790                               newinfo, tmp.num_counters,
1791                               compat_ptr(tmp.counters));
1792         if (ret)
1793                 goto free_newinfo_untrans;
1794         return 0;
1795
1796  free_newinfo_untrans:
1797         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
1798  free_newinfo:
1799         xt_free_table_info(newinfo);
1800         return ret;
1801 }
1802
1803 static int
1804 compat_do_ipt_set_ctl(struct sock *sk,  int cmd, void __user *user,
1805                 unsigned int len)
1806 {
1807         int ret;
1808
1809         if (!capable(CAP_NET_ADMIN))
1810                 return -EPERM;
1811
1812         switch (cmd) {
1813         case IPT_SO_SET_REPLACE:
1814                 ret = compat_do_replace(user, len);
1815                 break;
1816
1817         case IPT_SO_SET_ADD_COUNTERS:
1818                 ret = do_add_counters(user, len, 1);
1819                 break;
1820
1821         default:
1822                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
1823                 ret = -EINVAL;
1824         }
1825
1826         return ret;
1827 }
1828
1829 struct compat_ipt_get_entries
1830 {
1831         char name[IPT_TABLE_MAXNAMELEN];
1832         compat_uint_t size;
1833         struct compat_ipt_entry entrytable[0];
1834 };
1835
1836 static int compat_copy_entries_to_user(unsigned int total_size,
1837                      struct xt_table *table, void __user *userptr)
1838 {
1839         unsigned int off, num;
1840         struct compat_ipt_entry e;
1841         struct xt_counters *counters;
1842         struct xt_table_info *private = table->private;
1843         void __user *pos;
1844         unsigned int size;
1845         int ret = 0;
1846         void *loc_cpu_entry;
1847
1848         counters = alloc_counters(table);
1849         if (IS_ERR(counters))
1850                 return PTR_ERR(counters);
1851
1852         /* choose the copy that is on our node/cpu, ...
1853          * This choice is lazy (because current thread is
1854          * allowed to migrate to another cpu)
1855          */
1856         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1857         pos = userptr;
1858         size = total_size;
1859         ret = IPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1860                         compat_copy_entry_to_user, &pos, &size);
1861         if (ret)
1862                 goto free_counters;
1863
1864         /* ... then go back and fix counters and names */
1865         for (off = 0, num = 0; off < size; off += e.next_offset, num++) {
1866                 unsigned int i;
1867                 struct ipt_entry_match m;
1868                 struct ipt_entry_target t;
1869
1870                 ret = -EFAULT;
1871                 if (copy_from_user(&e, userptr + off,
1872                                         sizeof(struct compat_ipt_entry)))
1873                         goto free_counters;
1874                 if (copy_to_user(userptr + off +
1875                         offsetof(struct compat_ipt_entry, counters),
1876                          &counters[num], sizeof(counters[num])))
1877                         goto free_counters;
1878
1879                 for (i = sizeof(struct compat_ipt_entry);
1880                                 i < e.target_offset; i += m.u.match_size) {
1881                         if (copy_from_user(&m, userptr + off + i,
1882                                         sizeof(struct ipt_entry_match)))
1883                                 goto free_counters;
1884                         if (copy_to_user(userptr + off + i +
1885                                 offsetof(struct ipt_entry_match, u.user.name),
1886                                 m.u.kernel.match->name,
1887                                 strlen(m.u.kernel.match->name) + 1))
1888                                 goto free_counters;
1889                 }
1890
1891                 if (copy_from_user(&t, userptr + off + e.target_offset,
1892                                         sizeof(struct ipt_entry_target)))
1893                         goto free_counters;
1894                 if (copy_to_user(userptr + off + e.target_offset +
1895                         offsetof(struct ipt_entry_target, u.user.name),
1896                         t.u.kernel.target->name,
1897                         strlen(t.u.kernel.target->name) + 1))
1898                         goto free_counters;
1899         }
1900         ret = 0;
1901 free_counters:
1902         vfree(counters);
1903         return ret;
1904 }
1905
1906 static int
1907 compat_get_entries(struct compat_ipt_get_entries __user *uptr, int *len)
1908 {
1909         int ret;
1910         struct compat_ipt_get_entries get;
1911         struct xt_table *t;
1912
1913
1914         if (*len < sizeof(get)) {
1915                 duprintf("compat_get_entries: %u < %u\n",
1916                                 *len, (unsigned int)sizeof(get));
1917                 return -EINVAL;
1918         }
1919
1920         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1921                 return -EFAULT;
1922
1923         if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
1924                 duprintf("compat_get_entries: %u != %u\n", *len,
1925                         (unsigned int)(sizeof(struct compat_ipt_get_entries) +
1926                         get.size));
1927                 return -EINVAL;
1928         }
1929
1930         xt_compat_lock(AF_INET);
1931         t = xt_find_table_lock(AF_INET, get.name);
1932         if (t && !IS_ERR(t)) {
1933                 struct xt_table_info *private = t->private;
1934                 struct xt_table_info info;
1935                 duprintf("t->private->number = %u\n",
1936                          private->number);
1937                 ret = compat_table_info(private, &info);
1938                 if (!ret && get.size == info.size) {
1939                         ret = compat_copy_entries_to_user(private->size,
1940                                                    t, uptr->entrytable);
1941                 } else if (!ret) {
1942                         duprintf("compat_get_entries: I've got %u not %u!\n",
1943                                  private->size,
1944                                  get.size);
1945                         ret = -EINVAL;
1946                 }
1947                 compat_flush_offsets();
1948                 module_put(t->me);
1949                 xt_table_unlock(t);
1950         } else
1951                 ret = t ? PTR_ERR(t) : -ENOENT;
1952
1953         xt_compat_unlock(AF_INET);
1954         return ret;
1955 }
1956
1957 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1958
1959 static int
1960 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1961 {
1962         int ret;
1963
1964         if (!capable(CAP_NET_ADMIN))
1965                 return -EPERM;
1966
1967         switch (cmd) {
1968         case IPT_SO_GET_INFO:
1969                 ret = get_info(user, len, 1);
1970                 break;
1971         case IPT_SO_GET_ENTRIES:
1972                 ret = compat_get_entries(user, len);
1973                 break;
1974         default:
1975                 ret = do_ipt_get_ctl(sk, cmd, user, len);
1976         }
1977         return ret;
1978 }
1979 #endif
1980
1981 static int
1982 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1983 {
1984         int ret;
1985
1986         if (!capable(CAP_NET_ADMIN))
1987                 return -EPERM;
1988
1989         switch (cmd) {
1990         case IPT_SO_SET_REPLACE:
1991                 ret = do_replace(user, len);
1992                 break;
1993
1994         case IPT_SO_SET_ADD_COUNTERS:
1995                 ret = do_add_counters(user, len, 0);
1996                 break;
1997
1998         default:
1999                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
2000                 ret = -EINVAL;
2001         }
2002
2003         return ret;
2004 }
2005
2006 static int
2007 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2008 {
2009         int ret;
2010
2011         if (!capable(CAP_NET_ADMIN))
2012                 return -EPERM;
2013
2014         switch (cmd) {
2015         case IPT_SO_GET_INFO:
2016                 ret = get_info(user, len, 0);
2017                 break;
2018
2019         case IPT_SO_GET_ENTRIES:
2020                 ret = get_entries(user, len);
2021                 break;
2022
2023         case IPT_SO_GET_REVISION_MATCH:
2024         case IPT_SO_GET_REVISION_TARGET: {
2025                 struct ipt_get_revision rev;
2026                 int target;
2027
2028                 if (*len != sizeof(rev)) {
2029                         ret = -EINVAL;
2030                         break;
2031                 }
2032                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2033                         ret = -EFAULT;
2034                         break;
2035                 }
2036
2037                 if (cmd == IPT_SO_GET_REVISION_TARGET)
2038                         target = 1;
2039                 else
2040                         target = 0;
2041
2042                 try_then_request_module(xt_find_revision(AF_INET, rev.name,
2043                                                          rev.revision,
2044                                                          target, &ret),
2045                                         "ipt_%s", rev.name);
2046                 break;
2047         }
2048
2049         default:
2050                 duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
2051                 ret = -EINVAL;
2052         }
2053
2054         return ret;
2055 }
2056
2057 int ipt_register_table(struct xt_table *table, const struct ipt_replace *repl)
2058 {
2059         int ret;
2060         struct xt_table_info *newinfo;
2061         static struct xt_table_info bootstrap
2062                 = { 0, 0, 0, { 0 }, { 0 }, { } };
2063         void *loc_cpu_entry;
2064
2065         newinfo = xt_alloc_table_info(repl->size);
2066         if (!newinfo)
2067                 return -ENOMEM;
2068
2069         /* choose the copy on our node/cpu
2070          * but dont care of preemption
2071          */
2072         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2073         memcpy(loc_cpu_entry, repl->entries, repl->size);
2074
2075         ret = translate_table(table->name, table->valid_hooks,
2076                               newinfo, loc_cpu_entry, repl->size,
2077                               repl->num_entries,
2078                               repl->hook_entry,
2079                               repl->underflow);
2080         if (ret != 0) {
2081                 xt_free_table_info(newinfo);
2082                 return ret;
2083         }
2084
2085         ret = xt_register_table(table, &bootstrap, newinfo);
2086         if (ret != 0) {
2087                 xt_free_table_info(newinfo);
2088                 return ret;
2089         }
2090
2091         return 0;
2092 }
2093
2094 void ipt_unregister_table(struct xt_table *table)
2095 {
2096         struct xt_table_info *private;
2097         void *loc_cpu_entry;
2098
2099         private = xt_unregister_table(table);
2100
2101         /* Decrease module usage counts and free resources */
2102         loc_cpu_entry = private->entries[raw_smp_processor_id()];
2103         IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
2104         xt_free_table_info(private);
2105 }
2106
2107 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2108 static inline bool
2109 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2110                      u_int8_t type, u_int8_t code,
2111                      bool invert)
2112 {
2113         return ((test_type == 0xFF) || (type == test_type && code >= min_code && code <= max_code))
2114                 ^ invert;
2115 }
2116
2117 static bool
2118 icmp_match(const struct sk_buff *skb,
2119            const struct net_device *in,
2120            const struct net_device *out,
2121            const struct xt_match *match,
2122            const void *matchinfo,
2123            int offset,
2124            unsigned int protoff,
2125            bool *hotdrop)
2126 {
2127         struct icmphdr _icmph, *ic;
2128         const struct ipt_icmp *icmpinfo = matchinfo;
2129
2130         /* Must not be a fragment. */
2131         if (offset)
2132                 return false;
2133
2134         ic = skb_header_pointer(skb, protoff, sizeof(_icmph), &_icmph);
2135         if (ic == NULL) {
2136                 /* We've been asked to examine this packet, and we
2137                  * can't.  Hence, no choice but to drop.
2138                  */
2139                 duprintf("Dropping evil ICMP tinygram.\n");
2140                 *hotdrop = true;
2141                 return false;
2142         }
2143
2144         return icmp_type_code_match(icmpinfo->type,
2145                                     icmpinfo->code[0],
2146                                     icmpinfo->code[1],
2147                                     ic->type, ic->code,
2148                                     !!(icmpinfo->invflags&IPT_ICMP_INV));
2149 }
2150
2151 /* Called when user tries to insert an entry of this type. */
2152 static int
2153 icmp_checkentry(const char *tablename,
2154            const void *info,
2155            const struct xt_match *match,
2156            void *matchinfo,
2157            unsigned int hook_mask)
2158 {
2159         const struct ipt_icmp *icmpinfo = matchinfo;
2160
2161         /* Must specify no unknown invflags */
2162         return !(icmpinfo->invflags & ~IPT_ICMP_INV);
2163 }
2164
2165 /* The built-in targets: standard (NULL) and error. */
2166 static struct xt_target ipt_standard_target = {
2167         .name           = IPT_STANDARD_TARGET,
2168         .targetsize     = sizeof(int),
2169         .family         = AF_INET,
2170 #ifdef CONFIG_COMPAT
2171         .compatsize     = sizeof(compat_int_t),
2172         .compat_from_user = compat_standard_from_user,
2173         .compat_to_user = compat_standard_to_user,
2174 #endif
2175 };
2176
2177 static struct xt_target ipt_error_target = {
2178         .name           = IPT_ERROR_TARGET,
2179         .target         = ipt_error,
2180         .targetsize     = IPT_FUNCTION_MAXNAMELEN,
2181         .family         = AF_INET,
2182 };
2183
2184 static struct nf_sockopt_ops ipt_sockopts = {
2185         .pf             = PF_INET,
2186         .set_optmin     = IPT_BASE_CTL,
2187         .set_optmax     = IPT_SO_SET_MAX+1,
2188         .set            = do_ipt_set_ctl,
2189 #ifdef CONFIG_COMPAT
2190         .compat_set     = compat_do_ipt_set_ctl,
2191 #endif
2192         .get_optmin     = IPT_BASE_CTL,
2193         .get_optmax     = IPT_SO_GET_MAX+1,
2194         .get            = do_ipt_get_ctl,
2195 #ifdef CONFIG_COMPAT
2196         .compat_get     = compat_do_ipt_get_ctl,
2197 #endif
2198 };
2199
2200 static struct xt_match icmp_matchstruct = {
2201         .name           = "icmp",
2202         .match          = icmp_match,
2203         .matchsize      = sizeof(struct ipt_icmp),
2204         .proto          = IPPROTO_ICMP,
2205         .family         = AF_INET,
2206         .checkentry     = icmp_checkentry,
2207 };
2208
2209 static int __init ip_tables_init(void)
2210 {
2211         int ret;
2212
2213         ret = xt_proto_init(AF_INET);
2214         if (ret < 0)
2215                 goto err1;
2216
2217         /* Noone else will be downing sem now, so we won't sleep */
2218         ret = xt_register_target(&ipt_standard_target);
2219         if (ret < 0)
2220                 goto err2;
2221         ret = xt_register_target(&ipt_error_target);
2222         if (ret < 0)
2223                 goto err3;
2224         ret = xt_register_match(&icmp_matchstruct);
2225         if (ret < 0)
2226                 goto err4;
2227
2228         /* Register setsockopt */
2229         ret = nf_register_sockopt(&ipt_sockopts);
2230         if (ret < 0)
2231                 goto err5;
2232
2233         printk("ip_tables: (C) 2000-2006 Netfilter Core Team\n");
2234         return 0;
2235
2236 err5:
2237         xt_unregister_match(&icmp_matchstruct);
2238 err4:
2239         xt_unregister_target(&ipt_error_target);
2240 err3:
2241         xt_unregister_target(&ipt_standard_target);
2242 err2:
2243         xt_proto_fini(AF_INET);
2244 err1:
2245         return ret;
2246 }
2247
2248 static void __exit ip_tables_fini(void)
2249 {
2250         nf_unregister_sockopt(&ipt_sockopts);
2251
2252         xt_unregister_match(&icmp_matchstruct);
2253         xt_unregister_target(&ipt_error_target);
2254         xt_unregister_target(&ipt_standard_target);
2255
2256         xt_proto_fini(AF_INET);
2257 }
2258
2259 EXPORT_SYMBOL(ipt_register_table);
2260 EXPORT_SYMBOL(ipt_unregister_table);
2261 EXPORT_SYMBOL(ipt_do_table);
2262 module_init(ip_tables_init);
2263 module_exit(ip_tables_fini);