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regulator: Fix warning with CONFIG_BUG disabled
[zen-stable.git] / net / ipv4 / netfilter / arp_tables.c
blobe855fffaed95ba384a9b5bc2145fee888fcf6274
1 /*
2 * Packet matching code for ARP packets.
3 *
4 * Based heavily, if not almost entirely, upon ip_tables.c framework.
5 *
6 * Some ARP specific bits are:
7 *
8 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
9 *
10 */
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/capability.h>
16 #include <linux/if_arp.h>
17 #include <linux/kmod.h>
18 #include <linux/vmalloc.h>
19 #include <linux/proc_fs.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/mutex.h>
23 #include <linux/err.h>
24 #include <net/compat.h>
25 #include <net/sock.h>
26 #include <asm/uaccess.h>
27
28 #include <linux/netfilter/x_tables.h>
29 #include <linux/netfilter_arp/arp_tables.h>
30 #include "../../netfilter/xt_repldata.h"
31
32 MODULE_LICENSE("GPL");
33 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
34 MODULE_DESCRIPTION("arptables core");
35
36 /*#define DEBUG_ARP_TABLES*/
37 /*#define DEBUG_ARP_TABLES_USER*/
38
39 #ifdef DEBUG_ARP_TABLES
40 #define dprintf(format, args...) printk(format , ## args)
41 #else
42 #define dprintf(format, args...)
43 #endif
44
45 #ifdef DEBUG_ARP_TABLES_USER
46 #define duprintf(format, args...) printk(format , ## args)
47 #else
48 #define duprintf(format, args...)
49 #endif
50
51 #ifdef CONFIG_NETFILTER_DEBUG
52 #define ARP_NF_ASSERT(x) WARN_ON(!(x))
53 #else
54 #define ARP_NF_ASSERT(x)
55 #endif
56
57 void *arpt_alloc_initial_table(const struct xt_table *info)
58 {
59 return xt_alloc_initial_table(arpt, ARPT);
60 }
61 EXPORT_SYMBOL_GPL(arpt_alloc_initial_table);
62
63 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
64 const char *hdr_addr, int len)
65 {
66 int i, ret;
67
68 if (len > ARPT_DEV_ADDR_LEN_MAX)
69 len = ARPT_DEV_ADDR_LEN_MAX;
70
71 ret = 0;
72 for (i = 0; i < len; i++)
73 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
74
75 return ret != 0;
76 }
77
78 /*
79 * Unfortunatly, _b and _mask are not aligned to an int (or long int)
80 * Some arches dont care, unrolling the loop is a win on them.
81 * For other arches, we only have a 16bit alignement.
82 */
83 static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
84 {
85 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
86 unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
87 #else
88 unsigned long ret = 0;
89 const u16 *a = (const u16 *)_a;
90 const u16 *b = (const u16 *)_b;
91 const u16 *mask = (const u16 *)_mask;
92 int i;
93
94 for (i = 0; i < IFNAMSIZ/sizeof(u16); i++)
95 ret |= (a[i] ^ b[i]) & mask[i];
96 #endif
97 return ret;
98 }
99
100 /* Returns whether packet matches rule or not. */
101 static inline int arp_packet_match(const struct arphdr *arphdr,
102 struct net_device *dev,
103 const char *indev,
104 const char *outdev,
105 const struct arpt_arp *arpinfo)
106 {
107 const char *arpptr = (char *)(arphdr + 1);
108 const char *src_devaddr, *tgt_devaddr;
109 __be32 src_ipaddr, tgt_ipaddr;
110 long ret;
111
112 #define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
113
114 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
115 ARPT_INV_ARPOP)) {
116 dprintf("ARP operation field mismatch.\n");
117 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
118 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
119 return 0;
120 }
121
122 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
123 ARPT_INV_ARPHRD)) {
124 dprintf("ARP hardware address format mismatch.\n");
125 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
126 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
127 return 0;
128 }
129
130 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
131 ARPT_INV_ARPPRO)) {
132 dprintf("ARP protocol address format mismatch.\n");
133 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
134 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
135 return 0;
136 }
137
138 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
139 ARPT_INV_ARPHLN)) {
140 dprintf("ARP hardware address length mismatch.\n");
141 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
142 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
143 return 0;
144 }
145
146 src_devaddr = arpptr;
147 arpptr += dev->addr_len;
148 memcpy(&src_ipaddr, arpptr, sizeof(u32));
149 arpptr += sizeof(u32);
150 tgt_devaddr = arpptr;
151 arpptr += dev->addr_len;
152 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
153
154 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
155 ARPT_INV_SRCDEVADDR) ||
156 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
157 ARPT_INV_TGTDEVADDR)) {
158 dprintf("Source or target device address mismatch.\n");
159
160 return 0;
161 }
162
163 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
164 ARPT_INV_SRCIP) ||
165 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
166 ARPT_INV_TGTIP)) {
167 dprintf("Source or target IP address mismatch.\n");
168
169 dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
170 &src_ipaddr,
171 &arpinfo->smsk.s_addr,
172 &arpinfo->src.s_addr,
173 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
174 dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n",
175 &tgt_ipaddr,
176 &arpinfo->tmsk.s_addr,
177 &arpinfo->tgt.s_addr,
178 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
179 return 0;
180 }
181
182 /* Look for ifname matches. */
183 ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
184
185 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
186 dprintf("VIA in mismatch (%s vs %s).%s\n",
187 indev, arpinfo->iniface,
188 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
189 return 0;
190 }
191
192 ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
193
194 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
195 dprintf("VIA out mismatch (%s vs %s).%s\n",
196 outdev, arpinfo->outiface,
197 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
198 return 0;
199 }
200
201 return 1;
202 #undef FWINV
203 }
204
205 static inline int arp_checkentry(const struct arpt_arp *arp)
206 {
207 if (arp->flags & ~ARPT_F_MASK) {
208 duprintf("Unknown flag bits set: %08X\n",
209 arp->flags & ~ARPT_F_MASK);
210 return 0;
211 }
212 if (arp->invflags & ~ARPT_INV_MASK) {
213 duprintf("Unknown invflag bits set: %08X\n",
214 arp->invflags & ~ARPT_INV_MASK);
215 return 0;
216 }
217
218 return 1;
219 }
220
221 static unsigned int
222 arpt_error(struct sk_buff *skb, const struct xt_action_param *par)
223 {
224 if (net_ratelimit())
225 pr_err("arp_tables: error: '%s'\n",
226 (const char *)par->targinfo);
227
228 return NF_DROP;
229 }
230
231 static inline const struct xt_entry_target *
232 arpt_get_target_c(const struct arpt_entry *e)
233 {
234 return arpt_get_target((struct arpt_entry *)e);
235 }
236
237 static inline struct arpt_entry *
238 get_entry(const void *base, unsigned int offset)
239 {
240 return (struct arpt_entry *)(base + offset);
241 }
242
243 static inline __pure
244 struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry)
245 {
246 return (void *)entry + entry->next_offset;
247 }
248
249 unsigned int arpt_do_table(struct sk_buff *skb,
250 unsigned int hook,
251 const struct net_device *in,
252 const struct net_device *out,
253 struct xt_table *table)
254 {
255 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
256 unsigned int verdict = NF_DROP;
257 const struct arphdr *arp;
258 struct arpt_entry *e, *back;
259 const char *indev, *outdev;
260 void *table_base;
261 const struct xt_table_info *private;
262 struct xt_action_param acpar;
263
264 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
265 return NF_DROP;
266
267 indev = in ? in->name : nulldevname;
268 outdev = out ? out->name : nulldevname;
269
270 xt_info_rdlock_bh();
271 private = table->private;
272 table_base = private->entries[smp_processor_id()];
273
274 e = get_entry(table_base, private->hook_entry[hook]);
275 back = get_entry(table_base, private->underflow[hook]);
276
277 acpar.in = in;
278 acpar.out = out;
279 acpar.hooknum = hook;
280 acpar.family = NFPROTO_ARP;
281 acpar.hotdrop = false;
282
283 arp = arp_hdr(skb);
284 do {
285 const struct xt_entry_target *t;
286
287 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
288 e = arpt_next_entry(e);
289 continue;
290 }
291
292 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
293
294 t = arpt_get_target_c(e);
295
296 /* Standard target? */
297 if (!t->u.kernel.target->target) {
298 int v;
299
300 v = ((struct xt_standard_target *)t)->verdict;
301 if (v < 0) {
302 /* Pop from stack? */
303 if (v != XT_RETURN) {
304 verdict = (unsigned)(-v) - 1;
305 break;
306 }
307 e = back;
308 back = get_entry(table_base, back->comefrom);
309 continue;
310 }
311 if (table_base + v
312 != arpt_next_entry(e)) {
313 /* Save old back ptr in next entry */
314 struct arpt_entry *next = arpt_next_entry(e);
315 next->comefrom = (void *)back - table_base;
316
317 /* set back pointer to next entry */
318 back = next;
319 }
320
321 e = get_entry(table_base, v);
322 continue;
323 }
324
325 /* Targets which reenter must return
326 * abs. verdicts
327 */
328 acpar.target = t->u.kernel.target;
329 acpar.targinfo = t->data;
330 verdict = t->u.kernel.target->target(skb, &acpar);
331
332 /* Target might have changed stuff. */
333 arp = arp_hdr(skb);
334
335 if (verdict == XT_CONTINUE)
336 e = arpt_next_entry(e);
337 else
338 /* Verdict */
339 break;
340 } while (!acpar.hotdrop);
341 xt_info_rdunlock_bh();
342
343 if (acpar.hotdrop)
344 return NF_DROP;
345 else
346 return verdict;
347 }
348
349 /* All zeroes == unconditional rule. */
350 static inline bool unconditional(const struct arpt_arp *arp)
351 {
352 static const struct arpt_arp uncond;
353
354 return memcmp(arp, &uncond, sizeof(uncond)) == 0;
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 */
360 static int mark_source_chains(const 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 */
368 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
369 unsigned int pos = newinfo->hook_entry[hook];
370 struct arpt_entry *e
371 = (struct arpt_entry *)(entry0 + pos);
372
373 if (!(valid_hooks & (1 << hook)))
374 continue;
375
376 /* Set initial back pointer. */
377 e->counters.pcnt = pos;
378
379 for (;;) {
380 const struct xt_standard_target *t
381 = (void *)arpt_get_target_c(e);
382 int visited = e->comefrom & (1 << hook);
383
384 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
385 pr_notice("arptables: loop hook %u pos %u %08X.\n",
386 hook, pos, e->comefrom);
387 return 0;
388 }
389 e->comefrom
390 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
391
392 /* Unconditional return/END. */
393 if ((e->target_offset == sizeof(struct arpt_entry) &&
394 (strcmp(t->target.u.user.name,
395 XT_STANDARD_TARGET) == 0) &&
396 t->verdict < 0 && unconditional(&e->arp)) ||
397 visited) {
398 unsigned int oldpos, size;
399
400 if ((strcmp(t->target.u.user.name,
401 XT_STANDARD_TARGET) == 0) &&
402 t->verdict < -NF_MAX_VERDICT - 1) {
403 duprintf("mark_source_chains: bad "
404 "negative verdict (%i)\n",
405 t->verdict);
406 return 0;
407 }
408
409 /* Return: backtrack through the last
410 * big jump.
411 */
412 do {
413 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
414 oldpos = pos;
415 pos = e->counters.pcnt;
416 e->counters.pcnt = 0;
417
418 /* We're at the start. */
419 if (pos == oldpos)
420 goto next;
421
422 e = (struct arpt_entry *)
423 (entry0 + pos);
424 } while (oldpos == pos + e->next_offset);
425
426 /* Move along one */
427 size = e->next_offset;
428 e = (struct arpt_entry *)
429 (entry0 + pos + size);
430 e->counters.pcnt = pos;
431 pos += size;
432 } else {
433 int newpos = t->verdict;
434
435 if (strcmp(t->target.u.user.name,
436 XT_STANDARD_TARGET) == 0 &&
437 newpos >= 0) {
438 if (newpos > newinfo->size -
439 sizeof(struct arpt_entry)) {
440 duprintf("mark_source_chains: "
441 "bad verdict (%i)\n",
442 newpos);
443 return 0;
444 }
445
446 /* This a jump; chase it. */
447 duprintf("Jump rule %u -> %u\n",
448 pos, newpos);
449 } else {
450 /* ... this is a fallthru */
451 newpos = pos + e->next_offset;
452 }
453 e = (struct arpt_entry *)
454 (entry0 + newpos);
455 e->counters.pcnt = pos;
456 pos = newpos;
457 }
458 }
459 next:
460 duprintf("Finished chain %u\n", hook);
461 }
462 return 1;
463 }
464
465 static inline int check_entry(const struct arpt_entry *e, const char *name)
466 {
467 const struct xt_entry_target *t;
468
469 if (!arp_checkentry(&e->arp)) {
470 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
471 return -EINVAL;
472 }
473
474 if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
475 return -EINVAL;
476
477 t = arpt_get_target_c(e);
478 if (e->target_offset + t->u.target_size > e->next_offset)
479 return -EINVAL;
480
481 return 0;
482 }
483
484 static inline int check_target(struct arpt_entry *e, const char *name)
485 {
486 struct xt_entry_target *t = arpt_get_target(e);
487 int ret;
488 struct xt_tgchk_param par = {
489 .table = name,
490 .entryinfo = e,
491 .target = t->u.kernel.target,
492 .targinfo = t->data,
493 .hook_mask = e->comefrom,
494 .family = NFPROTO_ARP,
495 };
496
497 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
498 if (ret < 0) {
499 duprintf("arp_tables: check failed for `%s'.\n",
500 t->u.kernel.target->name);
501 return ret;
502 }
503 return 0;
504 }
505
506 static inline int
507 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
508 {
509 struct xt_entry_target *t;
510 struct xt_target *target;
511 int ret;
512
513 ret = check_entry(e, name);
514 if (ret)
515 return ret;
516
517 t = arpt_get_target(e);
518 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
519 t->u.user.revision);
520 if (IS_ERR(target)) {
521 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
522 ret = PTR_ERR(target);
523 goto out;
524 }
525 t->u.kernel.target = target;
526
527 ret = check_target(e, name);
528 if (ret)
529 goto err;
530 return 0;
531 err:
532 module_put(t->u.kernel.target->me);
533 out:
534 return ret;
535 }
536
537 static bool check_underflow(const struct arpt_entry *e)
538 {
539 const struct xt_entry_target *t;
540 unsigned int verdict;
541
542 if (!unconditional(&e->arp))
543 return false;
544 t = arpt_get_target_c(e);
545 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
546 return false;
547 verdict = ((struct xt_standard_target *)t)->verdict;
548 verdict = -verdict - 1;
549 return verdict == NF_DROP || verdict == NF_ACCEPT;
550 }
551
552 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
553 struct xt_table_info *newinfo,
554 const unsigned char *base,
555 const unsigned char *limit,
556 const unsigned int *hook_entries,
557 const unsigned int *underflows,
558 unsigned int valid_hooks)
559 {
560 unsigned int h;
561
562 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
563 (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
564 duprintf("Bad offset %p\n", e);
565 return -EINVAL;
566 }
567
568 if (e->next_offset
569 < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) {
570 duprintf("checking: element %p size %u\n",
571 e, e->next_offset);
572 return -EINVAL;
573 }
574
575 /* Check hooks & underflows */
576 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
577 if (!(valid_hooks & (1 << h)))
578 continue;
579 if ((unsigned char *)e - base == hook_entries[h])
580 newinfo->hook_entry[h] = hook_entries[h];
581 if ((unsigned char *)e - base == underflows[h]) {
582 if (!check_underflow(e)) {
583 pr_err("Underflows must be unconditional and "
584 "use the STANDARD target with "
585 "ACCEPT/DROP\n");
586 return -EINVAL;
587 }
588 newinfo->underflow[h] = underflows[h];
589 }
590 }
591
592 /* Clear counters and comefrom */
593 e->counters = ((struct xt_counters) { 0, 0 });
594 e->comefrom = 0;
595 return 0;
596 }
597
598 static inline void cleanup_entry(struct arpt_entry *e)
599 {
600 struct xt_tgdtor_param par;
601 struct xt_entry_target *t;
602
603 t = arpt_get_target(e);
604 par.target = t->u.kernel.target;
605 par.targinfo = t->data;
606 par.family = NFPROTO_ARP;
607 if (par.target->destroy != NULL)
608 par.target->destroy(&par);
609 module_put(par.target->me);
610 }
611
612 /* Checks and translates the user-supplied table segment (held in
613 * newinfo).
614 */
615 static int translate_table(struct xt_table_info *newinfo, void *entry0,
616 const struct arpt_replace *repl)
617 {
618 struct arpt_entry *iter;
619 unsigned int i;
620 int ret = 0;
621
622 newinfo->size = repl->size;
623 newinfo->number = repl->num_entries;
624
625 /* Init all hooks to impossible value. */
626 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
627 newinfo->hook_entry[i] = 0xFFFFFFFF;
628 newinfo->underflow[i] = 0xFFFFFFFF;
629 }
630
631 duprintf("translate_table: size %u\n", newinfo->size);
632 i = 0;
633
634 /* Walk through entries, checking offsets. */
635 xt_entry_foreach(iter, entry0, newinfo->size) {
636 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
637 entry0 + repl->size,
638 repl->hook_entry,
639 repl->underflow,
640 repl->valid_hooks);
641 if (ret != 0)
642 break;
643 ++i;
644 if (strcmp(arpt_get_target(iter)->u.user.name,
645 XT_ERROR_TARGET) == 0)
646 ++newinfo->stacksize;
647 }
648 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
649 if (ret != 0)
650 return ret;
651
652 if (i != repl->num_entries) {
653 duprintf("translate_table: %u not %u entries\n",
654 i, repl->num_entries);
655 return -EINVAL;
656 }
657
658 /* Check hooks all assigned */
659 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
660 /* Only hooks which are valid */
661 if (!(repl->valid_hooks & (1 << i)))
662 continue;
663 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
664 duprintf("Invalid hook entry %u %u\n",
665 i, repl->hook_entry[i]);
666 return -EINVAL;
667 }
668 if (newinfo->underflow[i] == 0xFFFFFFFF) {
669 duprintf("Invalid underflow %u %u\n",
670 i, repl->underflow[i]);
671 return -EINVAL;
672 }
673 }
674
675 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
676 duprintf("Looping hook\n");
677 return -ELOOP;
678 }
679
680 /* Finally, each sanity check must pass */
681 i = 0;
682 xt_entry_foreach(iter, entry0, newinfo->size) {
683 ret = find_check_entry(iter, repl->name, repl->size);
684 if (ret != 0)
685 break;
686 ++i;
687 }
688
689 if (ret != 0) {
690 xt_entry_foreach(iter, entry0, newinfo->size) {
691 if (i-- == 0)
692 break;
693 cleanup_entry(iter);
694 }
695 return ret;
696 }
697
698 /* And one copy for every other CPU */
699 for_each_possible_cpu(i) {
700 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
701 memcpy(newinfo->entries[i], entry0, newinfo->size);
702 }
703
704 return ret;
705 }
706
707 static void get_counters(const struct xt_table_info *t,
708 struct xt_counters counters[])
709 {
710 struct arpt_entry *iter;
711 unsigned int cpu;
712 unsigned int i;
713
714 for_each_possible_cpu(cpu) {
715 seqlock_t *lock = &per_cpu(xt_info_locks, cpu).lock;
716
717 i = 0;
718 xt_entry_foreach(iter, t->entries[cpu], t->size) {
719 u64 bcnt, pcnt;
720 unsigned int start;
721
722 do {
723 start = read_seqbegin(lock);
724 bcnt = iter->counters.bcnt;
725 pcnt = iter->counters.pcnt;
726 } while (read_seqretry(lock, start));
727
728 ADD_COUNTER(counters[i], bcnt, pcnt);
729 ++i;
730 }
731 }
732 }
733
734 static struct xt_counters *alloc_counters(const struct xt_table *table)
735 {
736 unsigned int countersize;
737 struct xt_counters *counters;
738 const struct xt_table_info *private = table->private;
739
740 /* We need atomic snapshot of counters: rest doesn't change
741 * (other than comefrom, which userspace doesn't care
742 * about).
743 */
744 countersize = sizeof(struct xt_counters) * private->number;
745 counters = vzalloc(countersize);
746
747 if (counters == NULL)
748 return ERR_PTR(-ENOMEM);
749
750 get_counters(private, counters);
751
752 return counters;
753 }
754
755 static int copy_entries_to_user(unsigned int total_size,
756 const struct xt_table *table,
757 void __user *userptr)
758 {
759 unsigned int off, num;
760 const struct arpt_entry *e;
761 struct xt_counters *counters;
762 struct xt_table_info *private = table->private;
763 int ret = 0;
764 void *loc_cpu_entry;
765
766 counters = alloc_counters(table);
767 if (IS_ERR(counters))
768 return PTR_ERR(counters);
769
770 loc_cpu_entry = private->entries[raw_smp_processor_id()];
771 /* ... then copy entire thing ... */
772 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
773 ret = -EFAULT;
774 goto free_counters;
775 }
776
777 /* FIXME: use iterator macros --RR */
778 /* ... then go back and fix counters and names */
779 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
780 const struct xt_entry_target *t;
781
782 e = (struct arpt_entry *)(loc_cpu_entry + off);
783 if (copy_to_user(userptr + off
784 + offsetof(struct arpt_entry, counters),
785 &counters[num],
786 sizeof(counters[num])) != 0) {
787 ret = -EFAULT;
788 goto free_counters;
789 }
790
791 t = arpt_get_target_c(e);
792 if (copy_to_user(userptr + off + e->target_offset
793 + offsetof(struct xt_entry_target,
794 u.user.name),
795 t->u.kernel.target->name,
796 strlen(t->u.kernel.target->name)+1) != 0) {
797 ret = -EFAULT;
798 goto free_counters;
799 }
800 }
801
802 free_counters:
803 vfree(counters);
804 return ret;
805 }
806
807 #ifdef CONFIG_COMPAT
808 static void compat_standard_from_user(void *dst, const void *src)
809 {
810 int v = *(compat_int_t *)src;
811
812 if (v > 0)
813 v += xt_compat_calc_jump(NFPROTO_ARP, v);
814 memcpy(dst, &v, sizeof(v));
815 }
816
817 static int compat_standard_to_user(void __user *dst, const void *src)
818 {
819 compat_int_t cv = *(int *)src;
820
821 if (cv > 0)
822 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
823 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
824 }
825
826 static int compat_calc_entry(const struct arpt_entry *e,
827 const struct xt_table_info *info,
828 const void *base, struct xt_table_info *newinfo)
829 {
830 const struct xt_entry_target *t;
831 unsigned int entry_offset;
832 int off, i, ret;
833
834 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
835 entry_offset = (void *)e - base;
836
837 t = arpt_get_target_c(e);
838 off += xt_compat_target_offset(t->u.kernel.target);
839 newinfo->size -= off;
840 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
841 if (ret)
842 return ret;
843
844 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
845 if (info->hook_entry[i] &&
846 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
847 newinfo->hook_entry[i] -= off;
848 if (info->underflow[i] &&
849 (e < (struct arpt_entry *)(base + info->underflow[i])))
850 newinfo->underflow[i] -= off;
851 }
852 return 0;
853 }
854
855 static int compat_table_info(const struct xt_table_info *info,
856 struct xt_table_info *newinfo)
857 {
858 struct arpt_entry *iter;
859 void *loc_cpu_entry;
860 int ret;
861
862 if (!newinfo || !info)
863 return -EINVAL;
864
865 /* we dont care about newinfo->entries[] */
866 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
867 newinfo->initial_entries = 0;
868 loc_cpu_entry = info->entries[raw_smp_processor_id()];
869 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
870 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
871 if (ret != 0)
872 return ret;
873 }
874 return 0;
875 }
876 #endif
877
878 static int get_info(struct net *net, void __user *user,
879 const int *len, int compat)
880 {
881 char name[XT_TABLE_MAXNAMELEN];
882 struct xt_table *t;
883 int ret;
884
885 if (*len != sizeof(struct arpt_getinfo)) {
886 duprintf("length %u != %Zu\n", *len,
887 sizeof(struct arpt_getinfo));
888 return -EINVAL;
889 }
890
891 if (copy_from_user(name, user, sizeof(name)) != 0)
892 return -EFAULT;
893
894 name[XT_TABLE_MAXNAMELEN-1] = '\0';
895 #ifdef CONFIG_COMPAT
896 if (compat)
897 xt_compat_lock(NFPROTO_ARP);
898 #endif
899 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
900 "arptable_%s", name);
901 if (t && !IS_ERR(t)) {
902 struct arpt_getinfo info;
903 const struct xt_table_info *private = t->private;
904 #ifdef CONFIG_COMPAT
905 struct xt_table_info tmp;
906
907 if (compat) {
908 ret = compat_table_info(private, &tmp);
909 xt_compat_flush_offsets(NFPROTO_ARP);
910 private = &tmp;
911 }
912 #endif
913 memset(&info, 0, sizeof(info));
914 info.valid_hooks = t->valid_hooks;
915 memcpy(info.hook_entry, private->hook_entry,
916 sizeof(info.hook_entry));
917 memcpy(info.underflow, private->underflow,
918 sizeof(info.underflow));
919 info.num_entries = private->number;
920 info.size = private->size;
921 strcpy(info.name, name);
922
923 if (copy_to_user(user, &info, *len) != 0)
924 ret = -EFAULT;
925 else
926 ret = 0;
927 xt_table_unlock(t);
928 module_put(t->me);
929 } else
930 ret = t ? PTR_ERR(t) : -ENOENT;
931 #ifdef CONFIG_COMPAT
932 if (compat)
933 xt_compat_unlock(NFPROTO_ARP);
934 #endif
935 return ret;
936 }
937
938 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
939 const int *len)
940 {
941 int ret;
942 struct arpt_get_entries get;
943 struct xt_table *t;
944
945 if (*len < sizeof(get)) {
946 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
947 return -EINVAL;
948 }
949 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
950 return -EFAULT;
951 if (*len != sizeof(struct arpt_get_entries) + get.size) {
952 duprintf("get_entries: %u != %Zu\n", *len,
953 sizeof(struct arpt_get_entries) + get.size);
954 return -EINVAL;
955 }
956
957 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
958 if (t && !IS_ERR(t)) {
959 const struct xt_table_info *private = t->private;
960
961 duprintf("t->private->number = %u\n",
962 private->number);
963 if (get.size == private->size)
964 ret = copy_entries_to_user(private->size,
965 t, uptr->entrytable);
966 else {
967 duprintf("get_entries: I've got %u not %u!\n",
968 private->size, get.size);
969 ret = -EAGAIN;
970 }
971 module_put(t->me);
972 xt_table_unlock(t);
973 } else
974 ret = t ? PTR_ERR(t) : -ENOENT;
975
976 return ret;
977 }
978
979 static int __do_replace(struct net *net, const char *name,
980 unsigned int valid_hooks,
981 struct xt_table_info *newinfo,
982 unsigned int num_counters,
983 void __user *counters_ptr)
984 {
985 int ret;
986 struct xt_table *t;
987 struct xt_table_info *oldinfo;
988 struct xt_counters *counters;
989 void *loc_cpu_old_entry;
990 struct arpt_entry *iter;
991
992 ret = 0;
993 counters = vzalloc(num_counters * sizeof(struct xt_counters));
994 if (!counters) {
995 ret = -ENOMEM;
996 goto out;
997 }
998
999 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1000 "arptable_%s", name);
1001 if (!t || IS_ERR(t)) {
1002 ret = t ? PTR_ERR(t) : -ENOENT;
1003 goto free_newinfo_counters_untrans;
1004 }
1005
1006 /* You lied! */
1007 if (valid_hooks != t->valid_hooks) {
1008 duprintf("Valid hook crap: %08X vs %08X\n",
1009 valid_hooks, t->valid_hooks);
1010 ret = -EINVAL;
1011 goto put_module;
1012 }
1013
1014 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1015 if (!oldinfo)
1016 goto put_module;
1017
1018 /* Update module usage count based on number of rules */
1019 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1020 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1021 if ((oldinfo->number > oldinfo->initial_entries) ||
1022 (newinfo->number <= oldinfo->initial_entries))
1023 module_put(t->me);
1024 if ((oldinfo->number > oldinfo->initial_entries) &&
1025 (newinfo->number <= oldinfo->initial_entries))
1026 module_put(t->me);
1027
1028 /* Get the old counters, and synchronize with replace */
1029 get_counters(oldinfo, counters);
1030
1031 /* Decrease module usage counts and free resource */
1032 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1033 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1034 cleanup_entry(iter);
1035
1036 xt_free_table_info(oldinfo);
1037 if (copy_to_user(counters_ptr, counters,
1038 sizeof(struct xt_counters) * num_counters) != 0)
1039 ret = -EFAULT;
1040 vfree(counters);
1041 xt_table_unlock(t);
1042 return ret;
1043
1044 put_module:
1045 module_put(t->me);
1046 xt_table_unlock(t);
1047 free_newinfo_counters_untrans:
1048 vfree(counters);
1049 out:
1050 return ret;
1051 }
1052
1053 static int do_replace(struct net *net, const void __user *user,
1054 unsigned int len)
1055 {
1056 int ret;
1057 struct arpt_replace tmp;
1058 struct xt_table_info *newinfo;
1059 void *loc_cpu_entry;
1060 struct arpt_entry *iter;
1061
1062 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1063 return -EFAULT;
1064
1065 /* overflow check */
1066 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1067 return -ENOMEM;
1068
1069 newinfo = xt_alloc_table_info(tmp.size);
1070 if (!newinfo)
1071 return -ENOMEM;
1072
1073 /* choose the copy that is on our node/cpu */
1074 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1075 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1076 tmp.size) != 0) {
1077 ret = -EFAULT;
1078 goto free_newinfo;
1079 }
1080
1081 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1082 if (ret != 0)
1083 goto free_newinfo;
1084
1085 duprintf("arp_tables: Translated table\n");
1086
1087 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1088 tmp.num_counters, tmp.counters);
1089 if (ret)
1090 goto free_newinfo_untrans;
1091 return 0;
1092
1093 free_newinfo_untrans:
1094 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1095 cleanup_entry(iter);
1096 free_newinfo:
1097 xt_free_table_info(newinfo);
1098 return ret;
1099 }
1100
1101 static int do_add_counters(struct net *net, const void __user *user,
1102 unsigned int len, int compat)
1103 {
1104 unsigned int i, curcpu;
1105 struct xt_counters_info tmp;
1106 struct xt_counters *paddc;
1107 unsigned int num_counters;
1108 const char *name;
1109 int size;
1110 void *ptmp;
1111 struct xt_table *t;
1112 const struct xt_table_info *private;
1113 int ret = 0;
1114 void *loc_cpu_entry;
1115 struct arpt_entry *iter;
1116 #ifdef CONFIG_COMPAT
1117 struct compat_xt_counters_info compat_tmp;
1118
1119 if (compat) {
1120 ptmp = &compat_tmp;
1121 size = sizeof(struct compat_xt_counters_info);
1122 } else
1123 #endif
1124 {
1125 ptmp = &tmp;
1126 size = sizeof(struct xt_counters_info);
1127 }
1128
1129 if (copy_from_user(ptmp, user, size) != 0)
1130 return -EFAULT;
1131
1132 #ifdef CONFIG_COMPAT
1133 if (compat) {
1134 num_counters = compat_tmp.num_counters;
1135 name = compat_tmp.name;
1136 } else
1137 #endif
1138 {
1139 num_counters = tmp.num_counters;
1140 name = tmp.name;
1141 }
1142
1143 if (len != size + num_counters * sizeof(struct xt_counters))
1144 return -EINVAL;
1145
1146 paddc = vmalloc(len - size);
1147 if (!paddc)
1148 return -ENOMEM;
1149
1150 if (copy_from_user(paddc, user + size, len - size) != 0) {
1151 ret = -EFAULT;
1152 goto free;
1153 }
1154
1155 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1156 if (!t || IS_ERR(t)) {
1157 ret = t ? PTR_ERR(t) : -ENOENT;
1158 goto free;
1159 }
1160
1161 local_bh_disable();
1162 private = t->private;
1163 if (private->number != num_counters) {
1164 ret = -EINVAL;
1165 goto unlock_up_free;
1166 }
1167
1168 i = 0;
1169 /* Choose the copy that is on our node */
1170 curcpu = smp_processor_id();
1171 loc_cpu_entry = private->entries[curcpu];
1172 xt_info_wrlock(curcpu);
1173 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1174 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1175 ++i;
1176 }
1177 xt_info_wrunlock(curcpu);
1178 unlock_up_free:
1179 local_bh_enable();
1180 xt_table_unlock(t);
1181 module_put(t->me);
1182 free:
1183 vfree(paddc);
1184
1185 return ret;
1186 }
1187
1188 #ifdef CONFIG_COMPAT
1189 static inline void compat_release_entry(struct compat_arpt_entry *e)
1190 {
1191 struct xt_entry_target *t;
1192
1193 t = compat_arpt_get_target(e);
1194 module_put(t->u.kernel.target->me);
1195 }
1196
1197 static inline int
1198 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1199 struct xt_table_info *newinfo,
1200 unsigned int *size,
1201 const unsigned char *base,
1202 const unsigned char *limit,
1203 const unsigned int *hook_entries,
1204 const unsigned int *underflows,
1205 const char *name)
1206 {
1207 struct xt_entry_target *t;
1208 struct xt_target *target;
1209 unsigned int entry_offset;
1210 int ret, off, h;
1211
1212 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1213 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1214 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1215 duprintf("Bad offset %p, limit = %p\n", e, limit);
1216 return -EINVAL;
1217 }
1218
1219 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1220 sizeof(struct compat_xt_entry_target)) {
1221 duprintf("checking: element %p size %u\n",
1222 e, e->next_offset);
1223 return -EINVAL;
1224 }
1225
1226 /* For purposes of check_entry casting the compat entry is fine */
1227 ret = check_entry((struct arpt_entry *)e, name);
1228 if (ret)
1229 return ret;
1230
1231 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1232 entry_offset = (void *)e - (void *)base;
1233
1234 t = compat_arpt_get_target(e);
1235 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1236 t->u.user.revision);
1237 if (IS_ERR(target)) {
1238 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1239 t->u.user.name);
1240 ret = PTR_ERR(target);
1241 goto out;
1242 }
1243 t->u.kernel.target = target;
1244
1245 off += xt_compat_target_offset(target);
1246 *size += off;
1247 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1248 if (ret)
1249 goto release_target;
1250
1251 /* Check hooks & underflows */
1252 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1253 if ((unsigned char *)e - base == hook_entries[h])
1254 newinfo->hook_entry[h] = hook_entries[h];
1255 if ((unsigned char *)e - base == underflows[h])
1256 newinfo->underflow[h] = underflows[h];
1257 }
1258
1259 /* Clear counters and comefrom */
1260 memset(&e->counters, 0, sizeof(e->counters));
1261 e->comefrom = 0;
1262 return 0;
1263
1264 release_target:
1265 module_put(t->u.kernel.target->me);
1266 out:
1267 return ret;
1268 }
1269
1270 static int
1271 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1272 unsigned int *size, const char *name,
1273 struct xt_table_info *newinfo, unsigned char *base)
1274 {
1275 struct xt_entry_target *t;
1276 struct xt_target *target;
1277 struct arpt_entry *de;
1278 unsigned int origsize;
1279 int ret, h;
1280
1281 ret = 0;
1282 origsize = *size;
1283 de = (struct arpt_entry *)*dstptr;
1284 memcpy(de, e, sizeof(struct arpt_entry));
1285 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1286
1287 *dstptr += sizeof(struct arpt_entry);
1288 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1289
1290 de->target_offset = e->target_offset - (origsize - *size);
1291 t = compat_arpt_get_target(e);
1292 target = t->u.kernel.target;
1293 xt_compat_target_from_user(t, dstptr, size);
1294
1295 de->next_offset = e->next_offset - (origsize - *size);
1296 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1297 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1298 newinfo->hook_entry[h] -= origsize - *size;
1299 if ((unsigned char *)de - base < newinfo->underflow[h])
1300 newinfo->underflow[h] -= origsize - *size;
1301 }
1302 return ret;
1303 }
1304
1305 static int translate_compat_table(const char *name,
1306 unsigned int valid_hooks,
1307 struct xt_table_info **pinfo,
1308 void **pentry0,
1309 unsigned int total_size,
1310 unsigned int number,
1311 unsigned int *hook_entries,
1312 unsigned int *underflows)
1313 {
1314 unsigned int i, j;
1315 struct xt_table_info *newinfo, *info;
1316 void *pos, *entry0, *entry1;
1317 struct compat_arpt_entry *iter0;
1318 struct arpt_entry *iter1;
1319 unsigned int size;
1320 int ret = 0;
1321
1322 info = *pinfo;
1323 entry0 = *pentry0;
1324 size = total_size;
1325 info->number = number;
1326
1327 /* Init all hooks to impossible value. */
1328 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1329 info->hook_entry[i] = 0xFFFFFFFF;
1330 info->underflow[i] = 0xFFFFFFFF;
1331 }
1332
1333 duprintf("translate_compat_table: size %u\n", info->size);
1334 j = 0;
1335 xt_compat_lock(NFPROTO_ARP);
1336 /* Walk through entries, checking offsets. */
1337 xt_entry_foreach(iter0, entry0, total_size) {
1338 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1339 entry0,
1340 entry0 + total_size,
1341 hook_entries,
1342 underflows,
1343 name);
1344 if (ret != 0)
1345 goto out_unlock;
1346 ++j;
1347 }
1348
1349 ret = -EINVAL;
1350 if (j != number) {
1351 duprintf("translate_compat_table: %u not %u entries\n",
1352 j, number);
1353 goto out_unlock;
1354 }
1355
1356 /* Check hooks all assigned */
1357 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1358 /* Only hooks which are valid */
1359 if (!(valid_hooks & (1 << i)))
1360 continue;
1361 if (info->hook_entry[i] == 0xFFFFFFFF) {
1362 duprintf("Invalid hook entry %u %u\n",
1363 i, hook_entries[i]);
1364 goto out_unlock;
1365 }
1366 if (info->underflow[i] == 0xFFFFFFFF) {
1367 duprintf("Invalid underflow %u %u\n",
1368 i, underflows[i]);
1369 goto out_unlock;
1370 }
1371 }
1372
1373 ret = -ENOMEM;
1374 newinfo = xt_alloc_table_info(size);
1375 if (!newinfo)
1376 goto out_unlock;
1377
1378 newinfo->number = number;
1379 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1380 newinfo->hook_entry[i] = info->hook_entry[i];
1381 newinfo->underflow[i] = info->underflow[i];
1382 }
1383 entry1 = newinfo->entries[raw_smp_processor_id()];
1384 pos = entry1;
1385 size = total_size;
1386 xt_entry_foreach(iter0, entry0, total_size) {
1387 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1388 name, newinfo, entry1);
1389 if (ret != 0)
1390 break;
1391 }
1392 xt_compat_flush_offsets(NFPROTO_ARP);
1393 xt_compat_unlock(NFPROTO_ARP);
1394 if (ret)
1395 goto free_newinfo;
1396
1397 ret = -ELOOP;
1398 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1399 goto free_newinfo;
1400
1401 i = 0;
1402 xt_entry_foreach(iter1, entry1, newinfo->size) {
1403 ret = check_target(iter1, name);
1404 if (ret != 0)
1405 break;
1406 ++i;
1407 if (strcmp(arpt_get_target(iter1)->u.user.name,
1408 XT_ERROR_TARGET) == 0)
1409 ++newinfo->stacksize;
1410 }
1411 if (ret) {
1412 /*
1413 * The first i matches need cleanup_entry (calls ->destroy)
1414 * because they had called ->check already. The other j-i
1415 * entries need only release.
1416 */
1417 int skip = i;
1418 j -= i;
1419 xt_entry_foreach(iter0, entry0, newinfo->size) {
1420 if (skip-- > 0)
1421 continue;
1422 if (j-- == 0)
1423 break;
1424 compat_release_entry(iter0);
1425 }
1426 xt_entry_foreach(iter1, entry1, newinfo->size) {
1427 if (i-- == 0)
1428 break;
1429 cleanup_entry(iter1);
1430 }
1431 xt_free_table_info(newinfo);
1432 return ret;
1433 }
1434
1435 /* And one copy for every other CPU */
1436 for_each_possible_cpu(i)
1437 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1438 memcpy(newinfo->entries[i], entry1, newinfo->size);
1439
1440 *pinfo = newinfo;
1441 *pentry0 = entry1;
1442 xt_free_table_info(info);
1443 return 0;
1444
1445 free_newinfo:
1446 xt_free_table_info(newinfo);
1447 out:
1448 xt_entry_foreach(iter0, entry0, total_size) {
1449 if (j-- == 0)
1450 break;
1451 compat_release_entry(iter0);
1452 }
1453 return ret;
1454 out_unlock:
1455 xt_compat_flush_offsets(NFPROTO_ARP);
1456 xt_compat_unlock(NFPROTO_ARP);
1457 goto out;
1458 }
1459
1460 struct compat_arpt_replace {
1461 char name[XT_TABLE_MAXNAMELEN];
1462 u32 valid_hooks;
1463 u32 num_entries;
1464 u32 size;
1465 u32 hook_entry[NF_ARP_NUMHOOKS];
1466 u32 underflow[NF_ARP_NUMHOOKS];
1467 u32 num_counters;
1468 compat_uptr_t counters;
1469 struct compat_arpt_entry entries[0];
1470 };
1471
1472 static int compat_do_replace(struct net *net, void __user *user,
1473 unsigned int len)
1474 {
1475 int ret;
1476 struct compat_arpt_replace tmp;
1477 struct xt_table_info *newinfo;
1478 void *loc_cpu_entry;
1479 struct arpt_entry *iter;
1480
1481 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1482 return -EFAULT;
1483
1484 /* overflow check */
1485 if (tmp.size >= INT_MAX / num_possible_cpus())
1486 return -ENOMEM;
1487 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1488 return -ENOMEM;
1489
1490 newinfo = xt_alloc_table_info(tmp.size);
1491 if (!newinfo)
1492 return -ENOMEM;
1493
1494 /* choose the copy that is on our node/cpu */
1495 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1496 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1497 ret = -EFAULT;
1498 goto free_newinfo;
1499 }
1500
1501 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1502 &newinfo, &loc_cpu_entry, tmp.size,
1503 tmp.num_entries, tmp.hook_entry,
1504 tmp.underflow);
1505 if (ret != 0)
1506 goto free_newinfo;
1507
1508 duprintf("compat_do_replace: Translated table\n");
1509
1510 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1511 tmp.num_counters, compat_ptr(tmp.counters));
1512 if (ret)
1513 goto free_newinfo_untrans;
1514 return 0;
1515
1516 free_newinfo_untrans:
1517 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1518 cleanup_entry(iter);
1519 free_newinfo:
1520 xt_free_table_info(newinfo);
1521 return ret;
1522 }
1523
1524 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1525 unsigned int len)
1526 {
1527 int ret;
1528
1529 if (!capable(CAP_NET_ADMIN))
1530 return -EPERM;
1531
1532 switch (cmd) {
1533 case ARPT_SO_SET_REPLACE:
1534 ret = compat_do_replace(sock_net(sk), user, len);
1535 break;
1536
1537 case ARPT_SO_SET_ADD_COUNTERS:
1538 ret = do_add_counters(sock_net(sk), user, len, 1);
1539 break;
1540
1541 default:
1542 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1543 ret = -EINVAL;
1544 }
1545
1546 return ret;
1547 }
1548
1549 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1550 compat_uint_t *size,
1551 struct xt_counters *counters,
1552 unsigned int i)
1553 {
1554 struct xt_entry_target *t;
1555 struct compat_arpt_entry __user *ce;
1556 u_int16_t target_offset, next_offset;
1557 compat_uint_t origsize;
1558 int ret;
1559
1560 origsize = *size;
1561 ce = (struct compat_arpt_entry __user *)*dstptr;
1562 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1563 copy_to_user(&ce->counters, &counters[i],
1564 sizeof(counters[i])) != 0)
1565 return -EFAULT;
1566
1567 *dstptr += sizeof(struct compat_arpt_entry);
1568 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1569
1570 target_offset = e->target_offset - (origsize - *size);
1571
1572 t = arpt_get_target(e);
1573 ret = xt_compat_target_to_user(t, dstptr, size);
1574 if (ret)
1575 return ret;
1576 next_offset = e->next_offset - (origsize - *size);
1577 if (put_user(target_offset, &ce->target_offset) != 0 ||
1578 put_user(next_offset, &ce->next_offset) != 0)
1579 return -EFAULT;
1580 return 0;
1581 }
1582
1583 static int compat_copy_entries_to_user(unsigned int total_size,
1584 struct xt_table *table,
1585 void __user *userptr)
1586 {
1587 struct xt_counters *counters;
1588 const struct xt_table_info *private = table->private;
1589 void __user *pos;
1590 unsigned int size;
1591 int ret = 0;
1592 void *loc_cpu_entry;
1593 unsigned int i = 0;
1594 struct arpt_entry *iter;
1595
1596 counters = alloc_counters(table);
1597 if (IS_ERR(counters))
1598 return PTR_ERR(counters);
1599
1600 /* choose the copy on our node/cpu */
1601 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1602 pos = userptr;
1603 size = total_size;
1604 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1605 ret = compat_copy_entry_to_user(iter, &pos,
1606 &size, counters, i++);
1607 if (ret != 0)
1608 break;
1609 }
1610 vfree(counters);
1611 return ret;
1612 }
1613
1614 struct compat_arpt_get_entries {
1615 char name[XT_TABLE_MAXNAMELEN];
1616 compat_uint_t size;
1617 struct compat_arpt_entry entrytable[0];
1618 };
1619
1620 static int compat_get_entries(struct net *net,
1621 struct compat_arpt_get_entries __user *uptr,
1622 int *len)
1623 {
1624 int ret;
1625 struct compat_arpt_get_entries get;
1626 struct xt_table *t;
1627
1628 if (*len < sizeof(get)) {
1629 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1630 return -EINVAL;
1631 }
1632 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1633 return -EFAULT;
1634 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1635 duprintf("compat_get_entries: %u != %zu\n",
1636 *len, sizeof(get) + get.size);
1637 return -EINVAL;
1638 }
1639
1640 xt_compat_lock(NFPROTO_ARP);
1641 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1642 if (t && !IS_ERR(t)) {
1643 const struct xt_table_info *private = t->private;
1644 struct xt_table_info info;
1645
1646 duprintf("t->private->number = %u\n", private->number);
1647 ret = compat_table_info(private, &info);
1648 if (!ret && get.size == info.size) {
1649 ret = compat_copy_entries_to_user(private->size,
1650 t, uptr->entrytable);
1651 } else if (!ret) {
1652 duprintf("compat_get_entries: I've got %u not %u!\n",
1653 private->size, get.size);
1654 ret = -EAGAIN;
1655 }
1656 xt_compat_flush_offsets(NFPROTO_ARP);
1657 module_put(t->me);
1658 xt_table_unlock(t);
1659 } else
1660 ret = t ? PTR_ERR(t) : -ENOENT;
1661
1662 xt_compat_unlock(NFPROTO_ARP);
1663 return ret;
1664 }
1665
1666 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1667
1668 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1669 int *len)
1670 {
1671 int ret;
1672
1673 if (!capable(CAP_NET_ADMIN))
1674 return -EPERM;
1675
1676 switch (cmd) {
1677 case ARPT_SO_GET_INFO:
1678 ret = get_info(sock_net(sk), user, len, 1);
1679 break;
1680 case ARPT_SO_GET_ENTRIES:
1681 ret = compat_get_entries(sock_net(sk), user, len);
1682 break;
1683 default:
1684 ret = do_arpt_get_ctl(sk, cmd, user, len);
1685 }
1686 return ret;
1687 }
1688 #endif
1689
1690 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1691 {
1692 int ret;
1693
1694 if (!capable(CAP_NET_ADMIN))
1695 return -EPERM;
1696
1697 switch (cmd) {
1698 case ARPT_SO_SET_REPLACE:
1699 ret = do_replace(sock_net(sk), user, len);
1700 break;
1701
1702 case ARPT_SO_SET_ADD_COUNTERS:
1703 ret = do_add_counters(sock_net(sk), user, len, 0);
1704 break;
1705
1706 default:
1707 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1708 ret = -EINVAL;
1709 }
1710
1711 return ret;
1712 }
1713
1714 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1715 {
1716 int ret;
1717
1718 if (!capable(CAP_NET_ADMIN))
1719 return -EPERM;
1720
1721 switch (cmd) {
1722 case ARPT_SO_GET_INFO:
1723 ret = get_info(sock_net(sk), user, len, 0);
1724 break;
1725
1726 case ARPT_SO_GET_ENTRIES:
1727 ret = get_entries(sock_net(sk), user, len);
1728 break;
1729
1730 case ARPT_SO_GET_REVISION_TARGET: {
1731 struct xt_get_revision rev;
1732
1733 if (*len != sizeof(rev)) {
1734 ret = -EINVAL;
1735 break;
1736 }
1737 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1738 ret = -EFAULT;
1739 break;
1740 }
1741
1742 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1743 rev.revision, 1, &ret),
1744 "arpt_%s", rev.name);
1745 break;
1746 }
1747
1748 default:
1749 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1750 ret = -EINVAL;
1751 }
1752
1753 return ret;
1754 }
1755
1756 struct xt_table *arpt_register_table(struct net *net,
1757 const struct xt_table *table,
1758 const struct arpt_replace *repl)
1759 {
1760 int ret;
1761 struct xt_table_info *newinfo;
1762 struct xt_table_info bootstrap = {0};
1763 void *loc_cpu_entry;
1764 struct xt_table *new_table;
1765
1766 newinfo = xt_alloc_table_info(repl->size);
1767 if (!newinfo) {
1768 ret = -ENOMEM;
1769 goto out;
1770 }
1771
1772 /* choose the copy on our node/cpu */
1773 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1774 memcpy(loc_cpu_entry, repl->entries, repl->size);
1775
1776 ret = translate_table(newinfo, loc_cpu_entry, repl);
1777 duprintf("arpt_register_table: translate table gives %d\n", ret);
1778 if (ret != 0)
1779 goto out_free;
1780
1781 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1782 if (IS_ERR(new_table)) {
1783 ret = PTR_ERR(new_table);
1784 goto out_free;
1785 }
1786 return new_table;
1787
1788 out_free:
1789 xt_free_table_info(newinfo);
1790 out:
1791 return ERR_PTR(ret);
1792 }
1793
1794 void arpt_unregister_table(struct xt_table *table)
1795 {
1796 struct xt_table_info *private;
1797 void *loc_cpu_entry;
1798 struct module *table_owner = table->me;
1799 struct arpt_entry *iter;
1800
1801 private = xt_unregister_table(table);
1802
1803 /* Decrease module usage counts and free resources */
1804 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1805 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1806 cleanup_entry(iter);
1807 if (private->number > private->initial_entries)
1808 module_put(table_owner);
1809 xt_free_table_info(private);
1810 }
1811
1812 /* The built-in targets: standard (NULL) and error. */
1813 static struct xt_target arpt_builtin_tg[] __read_mostly = {
1814 {
1815 .name = XT_STANDARD_TARGET,
1816 .targetsize = sizeof(int),
1817 .family = NFPROTO_ARP,
1818 #ifdef CONFIG_COMPAT
1819 .compatsize = sizeof(compat_int_t),
1820 .compat_from_user = compat_standard_from_user,
1821 .compat_to_user = compat_standard_to_user,
1822 #endif
1823 },
1824 {
1825 .name = XT_ERROR_TARGET,
1826 .target = arpt_error,
1827 .targetsize = XT_FUNCTION_MAXNAMELEN,
1828 .family = NFPROTO_ARP,
1829 },
1830 };
1831
1832 static struct nf_sockopt_ops arpt_sockopts = {
1833 .pf = PF_INET,
1834 .set_optmin = ARPT_BASE_CTL,
1835 .set_optmax = ARPT_SO_SET_MAX+1,
1836 .set = do_arpt_set_ctl,
1837 #ifdef CONFIG_COMPAT
1838 .compat_set = compat_do_arpt_set_ctl,
1839 #endif
1840 .get_optmin = ARPT_BASE_CTL,
1841 .get_optmax = ARPT_SO_GET_MAX+1,
1842 .get = do_arpt_get_ctl,
1843 #ifdef CONFIG_COMPAT
1844 .compat_get = compat_do_arpt_get_ctl,
1845 #endif
1846 .owner = THIS_MODULE,
1847 };
1848
1849 static int __net_init arp_tables_net_init(struct net *net)
1850 {
1851 return xt_proto_init(net, NFPROTO_ARP);
1852 }
1853
1854 static void __net_exit arp_tables_net_exit(struct net *net)
1855 {
1856 xt_proto_fini(net, NFPROTO_ARP);
1857 }
1858
1859 static struct pernet_operations arp_tables_net_ops = {
1860 .init = arp_tables_net_init,
1861 .exit = arp_tables_net_exit,
1862 };
1863
1864 static int __init arp_tables_init(void)
1865 {
1866 int ret;
1867
1868 ret = register_pernet_subsys(&arp_tables_net_ops);
1869 if (ret < 0)
1870 goto err1;
1871
1872 /* Noone else will be downing sem now, so we won't sleep */
1873 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1874 if (ret < 0)
1875 goto err2;
1876
1877 /* Register setsockopt */
1878 ret = nf_register_sockopt(&arpt_sockopts);
1879 if (ret < 0)
1880 goto err4;
1881
1882 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1883 return 0;
1884
1885 err4:
1886 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1887 err2:
1888 unregister_pernet_subsys(&arp_tables_net_ops);
1889 err1:
1890 return ret;
1891 }
1892
1893 static void __exit arp_tables_fini(void)
1894 {
1895 nf_unregister_sockopt(&arpt_sockopts);
1896 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1897 unregister_pernet_subsys(&arp_tables_net_ops);
1898 }
1899
1900 EXPORT_SYMBOL(arpt_register_table);
1901 EXPORT_SYMBOL(arpt_unregister_table);
1902 EXPORT_SYMBOL(arpt_do_table);
1903
1904 module_init(arp_tables_init);
1905 module_exit(arp_tables_fini);