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RT-AC56 3.0.0.4.374.37 core
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / net / ipv4 / netfilter / arp_tables.c
blobf57f8f5413f401437dd1d8cd3e751681c532f386
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 arpt_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 arpt_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 arpt_standard_target *)t)->verdict;
301 if (v < 0) {
302 /* Pop from stack? */
303 if (v != ARPT_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 == ARPT_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 arpt_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 ARPT_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 ARPT_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 ARPT_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 arpt_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 arpt_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 arpt_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 arpt_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 arpt_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 arpt_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 arpt_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 arpt_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 unsigned int curcpu = get_cpu();
714
715 /* Instead of clearing (by a previous call to memset())
716 * the counters and using adds, we set the counters
717 * with data used by 'current' CPU
718 *
719 * Bottom half has to be disabled to prevent deadlock
720 * if new softirq were to run and call ipt_do_table
721 */
722 local_bh_disable();
723 i = 0;
724 xt_entry_foreach(iter, t->entries[curcpu], t->size) {
725 SET_COUNTER(counters[i], iter->counters.bcnt,
726 iter->counters.pcnt);
727 ++i;
728 }
729 local_bh_enable();
730 /* Processing counters from other cpus, we can let bottom half enabled,
731 * (preemption is disabled)
732 */
733
734 for_each_possible_cpu(cpu) {
735 if (cpu == curcpu)
736 continue;
737 i = 0;
738 local_bh_disable();
739 xt_info_wrlock(cpu);
740 xt_entry_foreach(iter, t->entries[cpu], t->size) {
741 ADD_COUNTER(counters[i], iter->counters.bcnt,
742 iter->counters.pcnt);
743 ++i;
744 }
745 xt_info_wrunlock(cpu);
746 local_bh_enable();
747 }
748 put_cpu();
749 }
750
751 static struct xt_counters *alloc_counters(const struct xt_table *table)
752 {
753 unsigned int countersize;
754 struct xt_counters *counters;
755 const struct xt_table_info *private = table->private;
756
757 /* We need atomic snapshot of counters: rest doesn't change
758 * (other than comefrom, which userspace doesn't care
759 * about).
760 */
761 countersize = sizeof(struct xt_counters) * private->number;
762 counters = vmalloc(countersize);
763
764 if (counters == NULL)
765 return ERR_PTR(-ENOMEM);
766
767 get_counters(private, counters);
768
769 return counters;
770 }
771
772 static int copy_entries_to_user(unsigned int total_size,
773 const struct xt_table *table,
774 void __user *userptr)
775 {
776 unsigned int off, num;
777 const struct arpt_entry *e;
778 struct xt_counters *counters;
779 struct xt_table_info *private = table->private;
780 int ret = 0;
781 void *loc_cpu_entry;
782
783 counters = alloc_counters(table);
784 if (IS_ERR(counters))
785 return PTR_ERR(counters);
786
787 loc_cpu_entry = private->entries[raw_smp_processor_id()];
788 /* ... then copy entire thing ... */
789 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
790 ret = -EFAULT;
791 goto free_counters;
792 }
793
794 /* ... then go back and fix counters and names */
795 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
796 const struct arpt_entry_target *t;
797
798 e = (struct arpt_entry *)(loc_cpu_entry + off);
799 if (copy_to_user(userptr + off
800 + offsetof(struct arpt_entry, counters),
801 &counters[num],
802 sizeof(counters[num])) != 0) {
803 ret = -EFAULT;
804 goto free_counters;
805 }
806
807 t = arpt_get_target_c(e);
808 if (copy_to_user(userptr + off + e->target_offset
809 + offsetof(struct arpt_entry_target,
810 u.user.name),
811 t->u.kernel.target->name,
812 strlen(t->u.kernel.target->name)+1) != 0) {
813 ret = -EFAULT;
814 goto free_counters;
815 }
816 }
817
818 free_counters:
819 vfree(counters);
820 return ret;
821 }
822
823 #ifdef CONFIG_COMPAT
824 static void compat_standard_from_user(void *dst, const void *src)
825 {
826 int v = *(compat_int_t *)src;
827
828 if (v > 0)
829 v += xt_compat_calc_jump(NFPROTO_ARP, v);
830 memcpy(dst, &v, sizeof(v));
831 }
832
833 static int compat_standard_to_user(void __user *dst, const void *src)
834 {
835 compat_int_t cv = *(int *)src;
836
837 if (cv > 0)
838 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
839 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
840 }
841
842 static int compat_calc_entry(const struct arpt_entry *e,
843 const struct xt_table_info *info,
844 const void *base, struct xt_table_info *newinfo)
845 {
846 const struct arpt_entry_target *t;
847 unsigned int entry_offset;
848 int off, i, ret;
849
850 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
851 entry_offset = (void *)e - base;
852
853 t = arpt_get_target_c(e);
854 off += xt_compat_target_offset(t->u.kernel.target);
855 newinfo->size -= off;
856 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
857 if (ret)
858 return ret;
859
860 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
861 if (info->hook_entry[i] &&
862 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
863 newinfo->hook_entry[i] -= off;
864 if (info->underflow[i] &&
865 (e < (struct arpt_entry *)(base + info->underflow[i])))
866 newinfo->underflow[i] -= off;
867 }
868 return 0;
869 }
870
871 static int compat_table_info(const struct xt_table_info *info,
872 struct xt_table_info *newinfo)
873 {
874 struct arpt_entry *iter;
875 void *loc_cpu_entry;
876 int ret;
877
878 if (!newinfo || !info)
879 return -EINVAL;
880
881 /* we dont care about newinfo->entries[] */
882 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
883 newinfo->initial_entries = 0;
884 loc_cpu_entry = info->entries[raw_smp_processor_id()];
885 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
886 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
887 if (ret != 0)
888 return ret;
889 }
890 return 0;
891 }
892 #endif
893
894 static int get_info(struct net *net, void __user *user,
895 const int *len, int compat)
896 {
897 char name[ARPT_TABLE_MAXNAMELEN];
898 struct xt_table *t;
899 int ret;
900
901 if (*len != sizeof(struct arpt_getinfo)) {
902 duprintf("length %u != %Zu\n", *len,
903 sizeof(struct arpt_getinfo));
904 return -EINVAL;
905 }
906
907 if (copy_from_user(name, user, sizeof(name)) != 0)
908 return -EFAULT;
909
910 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
911 #ifdef CONFIG_COMPAT
912 if (compat)
913 xt_compat_lock(NFPROTO_ARP);
914 #endif
915 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
916 "arptable_%s", name);
917 if (t && !IS_ERR(t)) {
918 struct arpt_getinfo info;
919 const struct xt_table_info *private = t->private;
920 #ifdef CONFIG_COMPAT
921 struct xt_table_info tmp;
922
923 if (compat) {
924 ret = compat_table_info(private, &tmp);
925 xt_compat_flush_offsets(NFPROTO_ARP);
926 private = &tmp;
927 }
928 #endif
929 info.valid_hooks = t->valid_hooks;
930 memcpy(info.hook_entry, private->hook_entry,
931 sizeof(info.hook_entry));
932 memcpy(info.underflow, private->underflow,
933 sizeof(info.underflow));
934 info.num_entries = private->number;
935 info.size = private->size;
936 strcpy(info.name, name);
937
938 if (copy_to_user(user, &info, *len) != 0)
939 ret = -EFAULT;
940 else
941 ret = 0;
942 xt_table_unlock(t);
943 module_put(t->me);
944 } else
945 ret = t ? PTR_ERR(t) : -ENOENT;
946 #ifdef CONFIG_COMPAT
947 if (compat)
948 xt_compat_unlock(NFPROTO_ARP);
949 #endif
950 return ret;
951 }
952
953 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
954 const int *len)
955 {
956 int ret;
957 struct arpt_get_entries get;
958 struct xt_table *t;
959
960 if (*len < sizeof(get)) {
961 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
962 return -EINVAL;
963 }
964 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
965 return -EFAULT;
966 if (*len != sizeof(struct arpt_get_entries) + get.size) {
967 duprintf("get_entries: %u != %Zu\n", *len,
968 sizeof(struct arpt_get_entries) + get.size);
969 return -EINVAL;
970 }
971
972 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
973 if (t && !IS_ERR(t)) {
974 const struct xt_table_info *private = t->private;
975
976 duprintf("t->private->number = %u\n",
977 private->number);
978 if (get.size == private->size)
979 ret = copy_entries_to_user(private->size,
980 t, uptr->entrytable);
981 else {
982 duprintf("get_entries: I've got %u not %u!\n",
983 private->size, get.size);
984 ret = -EAGAIN;
985 }
986 module_put(t->me);
987 xt_table_unlock(t);
988 } else
989 ret = t ? PTR_ERR(t) : -ENOENT;
990
991 return ret;
992 }
993
994 static int __do_replace(struct net *net, const char *name,
995 unsigned int valid_hooks,
996 struct xt_table_info *newinfo,
997 unsigned int num_counters,
998 void __user *counters_ptr)
999 {
1000 int ret;
1001 struct xt_table *t;
1002 struct xt_table_info *oldinfo;
1003 struct xt_counters *counters;
1004 void *loc_cpu_old_entry;
1005 struct arpt_entry *iter;
1006
1007 ret = 0;
1008 counters = vmalloc(num_counters * sizeof(struct xt_counters));
1009 if (!counters) {
1010 ret = -ENOMEM;
1011 goto out;
1012 }
1013
1014 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1015 "arptable_%s", name);
1016 if (!t || IS_ERR(t)) {
1017 ret = t ? PTR_ERR(t) : -ENOENT;
1018 goto free_newinfo_counters_untrans;
1019 }
1020
1021 /* You lied! */
1022 if (valid_hooks != t->valid_hooks) {
1023 duprintf("Valid hook crap: %08X vs %08X\n",
1024 valid_hooks, t->valid_hooks);
1025 ret = -EINVAL;
1026 goto put_module;
1027 }
1028
1029 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1030 if (!oldinfo)
1031 goto put_module;
1032
1033 /* Update module usage count based on number of rules */
1034 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1035 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1036 if ((oldinfo->number > oldinfo->initial_entries) ||
1037 (newinfo->number <= oldinfo->initial_entries))
1038 module_put(t->me);
1039 if ((oldinfo->number > oldinfo->initial_entries) &&
1040 (newinfo->number <= oldinfo->initial_entries))
1041 module_put(t->me);
1042
1043 /* Get the old counters, and synchronize with replace */
1044 get_counters(oldinfo, counters);
1045
1046 /* Decrease module usage counts and free resource */
1047 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1048 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1049 cleanup_entry(iter);
1050
1051 xt_free_table_info(oldinfo);
1052 if (copy_to_user(counters_ptr, counters,
1053 sizeof(struct xt_counters) * num_counters) != 0)
1054 ret = -EFAULT;
1055 vfree(counters);
1056 xt_table_unlock(t);
1057 return ret;
1058
1059 put_module:
1060 module_put(t->me);
1061 xt_table_unlock(t);
1062 free_newinfo_counters_untrans:
1063 vfree(counters);
1064 out:
1065 return ret;
1066 }
1067
1068 static int do_replace(struct net *net, const void __user *user,
1069 unsigned int len)
1070 {
1071 int ret;
1072 struct arpt_replace tmp;
1073 struct xt_table_info *newinfo;
1074 void *loc_cpu_entry;
1075 struct arpt_entry *iter;
1076
1077 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1078 return -EFAULT;
1079
1080 /* overflow check */
1081 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1082 return -ENOMEM;
1083
1084 newinfo = xt_alloc_table_info(tmp.size);
1085 if (!newinfo)
1086 return -ENOMEM;
1087
1088 /* choose the copy that is on our node/cpu */
1089 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1090 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1091 tmp.size) != 0) {
1092 ret = -EFAULT;
1093 goto free_newinfo;
1094 }
1095
1096 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1097 if (ret != 0)
1098 goto free_newinfo;
1099
1100 duprintf("arp_tables: Translated table\n");
1101
1102 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1103 tmp.num_counters, tmp.counters);
1104 if (ret)
1105 goto free_newinfo_untrans;
1106 return 0;
1107
1108 free_newinfo_untrans:
1109 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1110 cleanup_entry(iter);
1111 free_newinfo:
1112 xt_free_table_info(newinfo);
1113 return ret;
1114 }
1115
1116 static int do_add_counters(struct net *net, const void __user *user,
1117 unsigned int len, int compat)
1118 {
1119 unsigned int i, curcpu;
1120 struct xt_counters_info tmp;
1121 struct xt_counters *paddc;
1122 unsigned int num_counters;
1123 const char *name;
1124 int size;
1125 void *ptmp;
1126 struct xt_table *t;
1127 const struct xt_table_info *private;
1128 int ret = 0;
1129 void *loc_cpu_entry;
1130 struct arpt_entry *iter;
1131 #ifdef CONFIG_COMPAT
1132 struct compat_xt_counters_info compat_tmp;
1133
1134 if (compat) {
1135 ptmp = &compat_tmp;
1136 size = sizeof(struct compat_xt_counters_info);
1137 } else
1138 #endif
1139 {
1140 ptmp = &tmp;
1141 size = sizeof(struct xt_counters_info);
1142 }
1143
1144 if (copy_from_user(ptmp, user, size) != 0)
1145 return -EFAULT;
1146
1147 #ifdef CONFIG_COMPAT
1148 if (compat) {
1149 num_counters = compat_tmp.num_counters;
1150 name = compat_tmp.name;
1151 } else
1152 #endif
1153 {
1154 num_counters = tmp.num_counters;
1155 name = tmp.name;
1156 }
1157
1158 if (len != size + num_counters * sizeof(struct xt_counters))
1159 return -EINVAL;
1160
1161 paddc = vmalloc(len - size);
1162 if (!paddc)
1163 return -ENOMEM;
1164
1165 if (copy_from_user(paddc, user + size, len - size) != 0) {
1166 ret = -EFAULT;
1167 goto free;
1168 }
1169
1170 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1171 if (!t || IS_ERR(t)) {
1172 ret = t ? PTR_ERR(t) : -ENOENT;
1173 goto free;
1174 }
1175
1176 local_bh_disable();
1177 private = t->private;
1178 if (private->number != num_counters) {
1179 ret = -EINVAL;
1180 goto unlock_up_free;
1181 }
1182
1183 i = 0;
1184 /* Choose the copy that is on our node */
1185 curcpu = smp_processor_id();
1186 loc_cpu_entry = private->entries[curcpu];
1187 xt_info_wrlock(curcpu);
1188 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1189 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1190 ++i;
1191 }
1192 xt_info_wrunlock(curcpu);
1193 unlock_up_free:
1194 local_bh_enable();
1195 xt_table_unlock(t);
1196 module_put(t->me);
1197 free:
1198 vfree(paddc);
1199
1200 return ret;
1201 }
1202
1203 #ifdef CONFIG_COMPAT
1204 static inline void compat_release_entry(struct compat_arpt_entry *e)
1205 {
1206 struct arpt_entry_target *t;
1207
1208 t = compat_arpt_get_target(e);
1209 module_put(t->u.kernel.target->me);
1210 }
1211
1212 static inline int
1213 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1214 struct xt_table_info *newinfo,
1215 unsigned int *size,
1216 const unsigned char *base,
1217 const unsigned char *limit,
1218 const unsigned int *hook_entries,
1219 const unsigned int *underflows,
1220 const char *name)
1221 {
1222 struct arpt_entry_target *t;
1223 struct xt_target *target;
1224 unsigned int entry_offset;
1225 int ret, off, h;
1226
1227 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1228 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1229 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1230 duprintf("Bad offset %p, limit = %p\n", e, limit);
1231 return -EINVAL;
1232 }
1233
1234 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1235 sizeof(struct compat_xt_entry_target)) {
1236 duprintf("checking: element %p size %u\n",
1237 e, e->next_offset);
1238 return -EINVAL;
1239 }
1240
1241 /* For purposes of check_entry casting the compat entry is fine */
1242 ret = check_entry((struct arpt_entry *)e, name);
1243 if (ret)
1244 return ret;
1245
1246 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1247 entry_offset = (void *)e - (void *)base;
1248
1249 t = compat_arpt_get_target(e);
1250 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1251 t->u.user.revision);
1252 if (IS_ERR(target)) {
1253 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1254 t->u.user.name);
1255 ret = PTR_ERR(target);
1256 goto out;
1257 }
1258 t->u.kernel.target = target;
1259
1260 off += xt_compat_target_offset(target);
1261 *size += off;
1262 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1263 if (ret)
1264 goto release_target;
1265
1266 /* Check hooks & underflows */
1267 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1268 if ((unsigned char *)e - base == hook_entries[h])
1269 newinfo->hook_entry[h] = hook_entries[h];
1270 if ((unsigned char *)e - base == underflows[h])
1271 newinfo->underflow[h] = underflows[h];
1272 }
1273
1274 /* Clear counters and comefrom */
1275 memset(&e->counters, 0, sizeof(e->counters));
1276 e->comefrom = 0;
1277 return 0;
1278
1279 release_target:
1280 module_put(t->u.kernel.target->me);
1281 out:
1282 return ret;
1283 }
1284
1285 static int
1286 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1287 unsigned int *size, const char *name,
1288 struct xt_table_info *newinfo, unsigned char *base)
1289 {
1290 struct arpt_entry_target *t;
1291 struct xt_target *target;
1292 struct arpt_entry *de;
1293 unsigned int origsize;
1294 int ret, h;
1295
1296 ret = 0;
1297 origsize = *size;
1298 de = (struct arpt_entry *)*dstptr;
1299 memcpy(de, e, sizeof(struct arpt_entry));
1300 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1301
1302 *dstptr += sizeof(struct arpt_entry);
1303 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1304
1305 de->target_offset = e->target_offset - (origsize - *size);
1306 t = compat_arpt_get_target(e);
1307 target = t->u.kernel.target;
1308 xt_compat_target_from_user(t, dstptr, size);
1309
1310 de->next_offset = e->next_offset - (origsize - *size);
1311 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1312 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1313 newinfo->hook_entry[h] -= origsize - *size;
1314 if ((unsigned char *)de - base < newinfo->underflow[h])
1315 newinfo->underflow[h] -= origsize - *size;
1316 }
1317 return ret;
1318 }
1319
1320 static int translate_compat_table(const char *name,
1321 unsigned int valid_hooks,
1322 struct xt_table_info **pinfo,
1323 void **pentry0,
1324 unsigned int total_size,
1325 unsigned int number,
1326 unsigned int *hook_entries,
1327 unsigned int *underflows)
1328 {
1329 unsigned int i, j;
1330 struct xt_table_info *newinfo, *info;
1331 void *pos, *entry0, *entry1;
1332 struct compat_arpt_entry *iter0;
1333 struct arpt_entry *iter1;
1334 unsigned int size;
1335 int ret = 0;
1336
1337 info = *pinfo;
1338 entry0 = *pentry0;
1339 size = total_size;
1340 info->number = number;
1341
1342 /* Init all hooks to impossible value. */
1343 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1344 info->hook_entry[i] = 0xFFFFFFFF;
1345 info->underflow[i] = 0xFFFFFFFF;
1346 }
1347
1348 duprintf("translate_compat_table: size %u\n", info->size);
1349 j = 0;
1350 xt_compat_lock(NFPROTO_ARP);
1351 /* Walk through entries, checking offsets. */
1352 xt_entry_foreach(iter0, entry0, total_size) {
1353 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1354 entry0,
1355 entry0 + total_size,
1356 hook_entries,
1357 underflows,
1358 name);
1359 if (ret != 0)
1360 goto out_unlock;
1361 ++j;
1362 }
1363
1364 ret = -EINVAL;
1365 if (j != number) {
1366 duprintf("translate_compat_table: %u not %u entries\n",
1367 j, number);
1368 goto out_unlock;
1369 }
1370
1371 /* Check hooks all assigned */
1372 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1373 /* Only hooks which are valid */
1374 if (!(valid_hooks & (1 << i)))
1375 continue;
1376 if (info->hook_entry[i] == 0xFFFFFFFF) {
1377 duprintf("Invalid hook entry %u %u\n",
1378 i, hook_entries[i]);
1379 goto out_unlock;
1380 }
1381 if (info->underflow[i] == 0xFFFFFFFF) {
1382 duprintf("Invalid underflow %u %u\n",
1383 i, underflows[i]);
1384 goto out_unlock;
1385 }
1386 }
1387
1388 ret = -ENOMEM;
1389 newinfo = xt_alloc_table_info(size);
1390 if (!newinfo)
1391 goto out_unlock;
1392
1393 newinfo->number = number;
1394 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1395 newinfo->hook_entry[i] = info->hook_entry[i];
1396 newinfo->underflow[i] = info->underflow[i];
1397 }
1398 entry1 = newinfo->entries[raw_smp_processor_id()];
1399 pos = entry1;
1400 size = total_size;
1401 xt_entry_foreach(iter0, entry0, total_size) {
1402 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1403 name, newinfo, entry1);
1404 if (ret != 0)
1405 break;
1406 }
1407 xt_compat_flush_offsets(NFPROTO_ARP);
1408 xt_compat_unlock(NFPROTO_ARP);
1409 if (ret)
1410 goto free_newinfo;
1411
1412 ret = -ELOOP;
1413 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1414 goto free_newinfo;
1415
1416 i = 0;
1417 xt_entry_foreach(iter1, entry1, newinfo->size) {
1418 ret = check_target(iter1, name);
1419 if (ret != 0)
1420 break;
1421 ++i;
1422 if (strcmp(arpt_get_target(iter1)->u.user.name,
1423 XT_ERROR_TARGET) == 0)
1424 ++newinfo->stacksize;
1425 }
1426 if (ret) {
1427 /*
1428 * The first i matches need cleanup_entry (calls ->destroy)
1429 * because they had called ->check already. The other j-i
1430 * entries need only release.
1431 */
1432 int skip = i;
1433 j -= i;
1434 xt_entry_foreach(iter0, entry0, newinfo->size) {
1435 if (skip-- > 0)
1436 continue;
1437 if (j-- == 0)
1438 break;
1439 compat_release_entry(iter0);
1440 }
1441 xt_entry_foreach(iter1, entry1, newinfo->size) {
1442 if (i-- == 0)
1443 break;
1444 cleanup_entry(iter1);
1445 }
1446 xt_free_table_info(newinfo);
1447 return ret;
1448 }
1449
1450 /* And one copy for every other CPU */
1451 for_each_possible_cpu(i)
1452 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1453 memcpy(newinfo->entries[i], entry1, newinfo->size);
1454
1455 *pinfo = newinfo;
1456 *pentry0 = entry1;
1457 xt_free_table_info(info);
1458 return 0;
1459
1460 free_newinfo:
1461 xt_free_table_info(newinfo);
1462 out:
1463 xt_entry_foreach(iter0, entry0, total_size) {
1464 if (j-- == 0)
1465 break;
1466 compat_release_entry(iter0);
1467 }
1468 return ret;
1469 out_unlock:
1470 xt_compat_flush_offsets(NFPROTO_ARP);
1471 xt_compat_unlock(NFPROTO_ARP);
1472 goto out;
1473 }
1474
1475 struct compat_arpt_replace {
1476 char name[ARPT_TABLE_MAXNAMELEN];
1477 u32 valid_hooks;
1478 u32 num_entries;
1479 u32 size;
1480 u32 hook_entry[NF_ARP_NUMHOOKS];
1481 u32 underflow[NF_ARP_NUMHOOKS];
1482 u32 num_counters;
1483 compat_uptr_t counters;
1484 struct compat_arpt_entry entries[0];
1485 };
1486
1487 static int compat_do_replace(struct net *net, void __user *user,
1488 unsigned int len)
1489 {
1490 int ret;
1491 struct compat_arpt_replace tmp;
1492 struct xt_table_info *newinfo;
1493 void *loc_cpu_entry;
1494 struct arpt_entry *iter;
1495
1496 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1497 return -EFAULT;
1498
1499 /* overflow check */
1500 if (tmp.size >= INT_MAX / num_possible_cpus())
1501 return -ENOMEM;
1502 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1503 return -ENOMEM;
1504
1505 newinfo = xt_alloc_table_info(tmp.size);
1506 if (!newinfo)
1507 return -ENOMEM;
1508
1509 /* choose the copy that is on our node/cpu */
1510 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1511 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1512 ret = -EFAULT;
1513 goto free_newinfo;
1514 }
1515
1516 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1517 &newinfo, &loc_cpu_entry, tmp.size,
1518 tmp.num_entries, tmp.hook_entry,
1519 tmp.underflow);
1520 if (ret != 0)
1521 goto free_newinfo;
1522
1523 duprintf("compat_do_replace: Translated table\n");
1524
1525 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1526 tmp.num_counters, compat_ptr(tmp.counters));
1527 if (ret)
1528 goto free_newinfo_untrans;
1529 return 0;
1530
1531 free_newinfo_untrans:
1532 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1533 cleanup_entry(iter);
1534 free_newinfo:
1535 xt_free_table_info(newinfo);
1536 return ret;
1537 }
1538
1539 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1540 unsigned int len)
1541 {
1542 int ret;
1543
1544 if (!capable(CAP_NET_ADMIN))
1545 return -EPERM;
1546
1547 switch (cmd) {
1548 case ARPT_SO_SET_REPLACE:
1549 ret = compat_do_replace(sock_net(sk), user, len);
1550 break;
1551
1552 case ARPT_SO_SET_ADD_COUNTERS:
1553 ret = do_add_counters(sock_net(sk), user, len, 1);
1554 break;
1555
1556 default:
1557 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1558 ret = -EINVAL;
1559 }
1560
1561 return ret;
1562 }
1563
1564 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1565 compat_uint_t *size,
1566 struct xt_counters *counters,
1567 unsigned int i)
1568 {
1569 struct arpt_entry_target *t;
1570 struct compat_arpt_entry __user *ce;
1571 u_int16_t target_offset, next_offset;
1572 compat_uint_t origsize;
1573 int ret;
1574
1575 origsize = *size;
1576 ce = (struct compat_arpt_entry __user *)*dstptr;
1577 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1578 copy_to_user(&ce->counters, &counters[i],
1579 sizeof(counters[i])) != 0)
1580 return -EFAULT;
1581
1582 *dstptr += sizeof(struct compat_arpt_entry);
1583 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1584
1585 target_offset = e->target_offset - (origsize - *size);
1586
1587 t = arpt_get_target(e);
1588 ret = xt_compat_target_to_user(t, dstptr, size);
1589 if (ret)
1590 return ret;
1591 next_offset = e->next_offset - (origsize - *size);
1592 if (put_user(target_offset, &ce->target_offset) != 0 ||
1593 put_user(next_offset, &ce->next_offset) != 0)
1594 return -EFAULT;
1595 return 0;
1596 }
1597
1598 static int compat_copy_entries_to_user(unsigned int total_size,
1599 struct xt_table *table,
1600 void __user *userptr)
1601 {
1602 struct xt_counters *counters;
1603 const struct xt_table_info *private = table->private;
1604 void __user *pos;
1605 unsigned int size;
1606 int ret = 0;
1607 void *loc_cpu_entry;
1608 unsigned int i = 0;
1609 struct arpt_entry *iter;
1610
1611 counters = alloc_counters(table);
1612 if (IS_ERR(counters))
1613 return PTR_ERR(counters);
1614
1615 /* choose the copy on our node/cpu */
1616 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1617 pos = userptr;
1618 size = total_size;
1619 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1620 ret = compat_copy_entry_to_user(iter, &pos,
1621 &size, counters, i++);
1622 if (ret != 0)
1623 break;
1624 }
1625 vfree(counters);
1626 return ret;
1627 }
1628
1629 struct compat_arpt_get_entries {
1630 char name[ARPT_TABLE_MAXNAMELEN];
1631 compat_uint_t size;
1632 struct compat_arpt_entry entrytable[0];
1633 };
1634
1635 static int compat_get_entries(struct net *net,
1636 struct compat_arpt_get_entries __user *uptr,
1637 int *len)
1638 {
1639 int ret;
1640 struct compat_arpt_get_entries get;
1641 struct xt_table *t;
1642
1643 if (*len < sizeof(get)) {
1644 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1645 return -EINVAL;
1646 }
1647 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1648 return -EFAULT;
1649 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1650 duprintf("compat_get_entries: %u != %zu\n",
1651 *len, sizeof(get) + get.size);
1652 return -EINVAL;
1653 }
1654
1655 xt_compat_lock(NFPROTO_ARP);
1656 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1657 if (t && !IS_ERR(t)) {
1658 const struct xt_table_info *private = t->private;
1659 struct xt_table_info info;
1660
1661 duprintf("t->private->number = %u\n", private->number);
1662 ret = compat_table_info(private, &info);
1663 if (!ret && get.size == info.size) {
1664 ret = compat_copy_entries_to_user(private->size,
1665 t, uptr->entrytable);
1666 } else if (!ret) {
1667 duprintf("compat_get_entries: I've got %u not %u!\n",
1668 private->size, get.size);
1669 ret = -EAGAIN;
1670 }
1671 xt_compat_flush_offsets(NFPROTO_ARP);
1672 module_put(t->me);
1673 xt_table_unlock(t);
1674 } else
1675 ret = t ? PTR_ERR(t) : -ENOENT;
1676
1677 xt_compat_unlock(NFPROTO_ARP);
1678 return ret;
1679 }
1680
1681 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1682
1683 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1684 int *len)
1685 {
1686 int ret;
1687
1688 if (!capable(CAP_NET_ADMIN))
1689 return -EPERM;
1690
1691 switch (cmd) {
1692 case ARPT_SO_GET_INFO:
1693 ret = get_info(sock_net(sk), user, len, 1);
1694 break;
1695 case ARPT_SO_GET_ENTRIES:
1696 ret = compat_get_entries(sock_net(sk), user, len);
1697 break;
1698 default:
1699 ret = do_arpt_get_ctl(sk, cmd, user, len);
1700 }
1701 return ret;
1702 }
1703 #endif
1704
1705 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1706 {
1707 int ret;
1708
1709 if (!capable(CAP_NET_ADMIN))
1710 return -EPERM;
1711
1712 switch (cmd) {
1713 case ARPT_SO_SET_REPLACE:
1714 ret = do_replace(sock_net(sk), user, len);
1715 break;
1716
1717 case ARPT_SO_SET_ADD_COUNTERS:
1718 ret = do_add_counters(sock_net(sk), user, len, 0);
1719 break;
1720
1721 default:
1722 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1723 ret = -EINVAL;
1724 }
1725
1726 return ret;
1727 }
1728
1729 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1730 {
1731 int ret;
1732
1733 if (!capable(CAP_NET_ADMIN))
1734 return -EPERM;
1735
1736 switch (cmd) {
1737 case ARPT_SO_GET_INFO:
1738 ret = get_info(sock_net(sk), user, len, 0);
1739 break;
1740
1741 case ARPT_SO_GET_ENTRIES:
1742 ret = get_entries(sock_net(sk), user, len);
1743 break;
1744
1745 case ARPT_SO_GET_REVISION_TARGET: {
1746 struct xt_get_revision rev;
1747
1748 if (*len != sizeof(rev)) {
1749 ret = -EINVAL;
1750 break;
1751 }
1752 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1753 ret = -EFAULT;
1754 break;
1755 }
1756
1757 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1758 rev.revision, 1, &ret),
1759 "arpt_%s", rev.name);
1760 break;
1761 }
1762
1763 default:
1764 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1765 ret = -EINVAL;
1766 }
1767
1768 return ret;
1769 }
1770
1771 struct xt_table *arpt_register_table(struct net *net,
1772 const struct xt_table *table,
1773 const struct arpt_replace *repl)
1774 {
1775 int ret;
1776 struct xt_table_info *newinfo;
1777 struct xt_table_info bootstrap = {0};
1778 void *loc_cpu_entry;
1779 struct xt_table *new_table;
1780
1781 newinfo = xt_alloc_table_info(repl->size);
1782 if (!newinfo) {
1783 ret = -ENOMEM;
1784 goto out;
1785 }
1786
1787 /* choose the copy on our node/cpu */
1788 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1789 memcpy(loc_cpu_entry, repl->entries, repl->size);
1790
1791 ret = translate_table(newinfo, loc_cpu_entry, repl);
1792 duprintf("arpt_register_table: translate table gives %d\n", ret);
1793 if (ret != 0)
1794 goto out_free;
1795
1796 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1797 if (IS_ERR(new_table)) {
1798 ret = PTR_ERR(new_table);
1799 goto out_free;
1800 }
1801 return new_table;
1802
1803 out_free:
1804 xt_free_table_info(newinfo);
1805 out:
1806 return ERR_PTR(ret);
1807 }
1808
1809 void arpt_unregister_table(struct xt_table *table)
1810 {
1811 struct xt_table_info *private;
1812 void *loc_cpu_entry;
1813 struct module *table_owner = table->me;
1814 struct arpt_entry *iter;
1815
1816 private = xt_unregister_table(table);
1817
1818 /* Decrease module usage counts and free resources */
1819 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1820 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1821 cleanup_entry(iter);
1822 if (private->number > private->initial_entries)
1823 module_put(table_owner);
1824 xt_free_table_info(private);
1825 }
1826
1827 /* The built-in targets: standard (NULL) and error. */
1828 static struct xt_target arpt_builtin_tg[] __read_mostly = {
1829 {
1830 .name = ARPT_STANDARD_TARGET,
1831 .targetsize = sizeof(int),
1832 .family = NFPROTO_ARP,
1833 #ifdef CONFIG_COMPAT
1834 .compatsize = sizeof(compat_int_t),
1835 .compat_from_user = compat_standard_from_user,
1836 .compat_to_user = compat_standard_to_user,
1837 #endif
1838 },
1839 {
1840 .name = ARPT_ERROR_TARGET,
1841 .target = arpt_error,
1842 .targetsize = ARPT_FUNCTION_MAXNAMELEN,
1843 .family = NFPROTO_ARP,
1844 },
1845 };
1846
1847 static struct nf_sockopt_ops arpt_sockopts = {
1848 .pf = PF_INET,
1849 .set_optmin = ARPT_BASE_CTL,
1850 .set_optmax = ARPT_SO_SET_MAX+1,
1851 .set = do_arpt_set_ctl,
1852 #ifdef CONFIG_COMPAT
1853 .compat_set = compat_do_arpt_set_ctl,
1854 #endif
1855 .get_optmin = ARPT_BASE_CTL,
1856 .get_optmax = ARPT_SO_GET_MAX+1,
1857 .get = do_arpt_get_ctl,
1858 #ifdef CONFIG_COMPAT
1859 .compat_get = compat_do_arpt_get_ctl,
1860 #endif
1861 .owner = THIS_MODULE,
1862 };
1863
1864 static int __net_init arp_tables_net_init(struct net *net)
1865 {
1866 return xt_proto_init(net, NFPROTO_ARP);
1867 }
1868
1869 static void __net_exit arp_tables_net_exit(struct net *net)
1870 {
1871 xt_proto_fini(net, NFPROTO_ARP);
1872 }
1873
1874 static struct pernet_operations arp_tables_net_ops = {
1875 .init = arp_tables_net_init,
1876 .exit = arp_tables_net_exit,
1877 };
1878
1879 static int __init arp_tables_init(void)
1880 {
1881 int ret;
1882
1883 ret = register_pernet_subsys(&arp_tables_net_ops);
1884 if (ret < 0)
1885 goto err1;
1886
1887 /* Noone else will be downing sem now, so we won't sleep */
1888 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1889 if (ret < 0)
1890 goto err2;
1891
1892 /* Register setsockopt */
1893 ret = nf_register_sockopt(&arpt_sockopts);
1894 if (ret < 0)
1895 goto err4;
1896
1897 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1898 return 0;
1899
1900 err4:
1901 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1902 err2:
1903 unregister_pernet_subsys(&arp_tables_net_ops);
1904 err1:
1905 return ret;
1906 }
1907
1908 static void __exit arp_tables_fini(void)
1909 {
1910 nf_unregister_sockopt(&arpt_sockopts);
1911 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1912 unregister_pernet_subsys(&arp_tables_net_ops);
1913 }
1914
1915 EXPORT_SYMBOL(arpt_register_table);
1916 EXPORT_SYMBOL(arpt_unregister_table);
1917 EXPORT_SYMBOL(arpt_do_table);
1918
1919 module_init(arp_tables_init);
1920 module_exit(arp_tables_fini);
Tomato firmware and modifications.