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staging: brcm80211: cleanup of transmit buffer size related wrapper function
[zen-stable.git] / net / ipv4 / netfilter / arp_tables.c
blobfd7a3f68917f1c53e4e8f6051eaa1e4ed728c2b3
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 * Unfortunately, _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 unsigned int addend;
264
265 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
266 return NF_DROP;
267
268 indev = in ? in->name : nulldevname;
269 outdev = out ? out->name : nulldevname;
270
271 local_bh_disable();
272 addend = xt_write_recseq_begin();
273 private = table->private;
274 table_base = private->entries[smp_processor_id()];
275
276 e = get_entry(table_base, private->hook_entry[hook]);
277 back = get_entry(table_base, private->underflow[hook]);
278
279 acpar.in = in;
280 acpar.out = out;
281 acpar.hooknum = hook;
282 acpar.family = NFPROTO_ARP;
283 acpar.hotdrop = false;
284
285 arp = arp_hdr(skb);
286 do {
287 const struct xt_entry_target *t;
288
289 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
290 e = arpt_next_entry(e);
291 continue;
292 }
293
294 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
295
296 t = arpt_get_target_c(e);
297
298 /* Standard target? */
299 if (!t->u.kernel.target->target) {
300 int v;
301
302 v = ((struct xt_standard_target *)t)->verdict;
303 if (v < 0) {
304 /* Pop from stack? */
305 if (v != XT_RETURN) {
306 verdict = (unsigned)(-v) - 1;
307 break;
308 }
309 e = back;
310 back = get_entry(table_base, back->comefrom);
311 continue;
312 }
313 if (table_base + v
314 != arpt_next_entry(e)) {
315 /* Save old back ptr in next entry */
316 struct arpt_entry *next = arpt_next_entry(e);
317 next->comefrom = (void *)back - table_base;
318
319 /* set back pointer to next entry */
320 back = next;
321 }
322
323 e = get_entry(table_base, v);
324 continue;
325 }
326
327 /* Targets which reenter must return
328 * abs. verdicts
329 */
330 acpar.target = t->u.kernel.target;
331 acpar.targinfo = t->data;
332 verdict = t->u.kernel.target->target(skb, &acpar);
333
334 /* Target might have changed stuff. */
335 arp = arp_hdr(skb);
336
337 if (verdict == XT_CONTINUE)
338 e = arpt_next_entry(e);
339 else
340 /* Verdict */
341 break;
342 } while (!acpar.hotdrop);
343 xt_write_recseq_end(addend);
344 local_bh_enable();
345
346 if (acpar.hotdrop)
347 return NF_DROP;
348 else
349 return verdict;
350 }
351
352 /* All zeroes == unconditional rule. */
353 static inline bool unconditional(const struct arpt_arp *arp)
354 {
355 static const struct arpt_arp uncond;
356
357 return memcmp(arp, &uncond, sizeof(uncond)) == 0;
358 }
359
360 /* Figures out from what hook each rule can be called: returns 0 if
361 * there are loops. Puts hook bitmask in comefrom.
362 */
363 static int mark_source_chains(const struct xt_table_info *newinfo,
364 unsigned int valid_hooks, void *entry0)
365 {
366 unsigned int hook;
367
368 /* No recursion; use packet counter to save back ptrs (reset
369 * to 0 as we leave), and comefrom to save source hook bitmask.
370 */
371 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
372 unsigned int pos = newinfo->hook_entry[hook];
373 struct arpt_entry *e
374 = (struct arpt_entry *)(entry0 + pos);
375
376 if (!(valid_hooks & (1 << hook)))
377 continue;
378
379 /* Set initial back pointer. */
380 e->counters.pcnt = pos;
381
382 for (;;) {
383 const struct xt_standard_target *t
384 = (void *)arpt_get_target_c(e);
385 int visited = e->comefrom & (1 << hook);
386
387 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
388 pr_notice("arptables: loop hook %u pos %u %08X.\n",
389 hook, pos, e->comefrom);
390 return 0;
391 }
392 e->comefrom
393 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
394
395 /* Unconditional return/END. */
396 if ((e->target_offset == sizeof(struct arpt_entry) &&
397 (strcmp(t->target.u.user.name,
398 XT_STANDARD_TARGET) == 0) &&
399 t->verdict < 0 && unconditional(&e->arp)) ||
400 visited) {
401 unsigned int oldpos, size;
402
403 if ((strcmp(t->target.u.user.name,
404 XT_STANDARD_TARGET) == 0) &&
405 t->verdict < -NF_MAX_VERDICT - 1) {
406 duprintf("mark_source_chains: bad "
407 "negative verdict (%i)\n",
408 t->verdict);
409 return 0;
410 }
411
412 /* Return: backtrack through the last
413 * big jump.
414 */
415 do {
416 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
417 oldpos = pos;
418 pos = e->counters.pcnt;
419 e->counters.pcnt = 0;
420
421 /* We're at the start. */
422 if (pos == oldpos)
423 goto next;
424
425 e = (struct arpt_entry *)
426 (entry0 + pos);
427 } while (oldpos == pos + e->next_offset);
428
429 /* Move along one */
430 size = e->next_offset;
431 e = (struct arpt_entry *)
432 (entry0 + pos + size);
433 e->counters.pcnt = pos;
434 pos += size;
435 } else {
436 int newpos = t->verdict;
437
438 if (strcmp(t->target.u.user.name,
439 XT_STANDARD_TARGET) == 0 &&
440 newpos >= 0) {
441 if (newpos > newinfo->size -
442 sizeof(struct arpt_entry)) {
443 duprintf("mark_source_chains: "
444 "bad verdict (%i)\n",
445 newpos);
446 return 0;
447 }
448
449 /* This a jump; chase it. */
450 duprintf("Jump rule %u -> %u\n",
451 pos, newpos);
452 } else {
453 /* ... this is a fallthru */
454 newpos = pos + e->next_offset;
455 }
456 e = (struct arpt_entry *)
457 (entry0 + newpos);
458 e->counters.pcnt = pos;
459 pos = newpos;
460 }
461 }
462 next:
463 duprintf("Finished chain %u\n", hook);
464 }
465 return 1;
466 }
467
468 static inline int check_entry(const struct arpt_entry *e, const char *name)
469 {
470 const struct xt_entry_target *t;
471
472 if (!arp_checkentry(&e->arp)) {
473 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
474 return -EINVAL;
475 }
476
477 if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
478 return -EINVAL;
479
480 t = arpt_get_target_c(e);
481 if (e->target_offset + t->u.target_size > e->next_offset)
482 return -EINVAL;
483
484 return 0;
485 }
486
487 static inline int check_target(struct arpt_entry *e, const char *name)
488 {
489 struct xt_entry_target *t = arpt_get_target(e);
490 int ret;
491 struct xt_tgchk_param par = {
492 .table = name,
493 .entryinfo = e,
494 .target = t->u.kernel.target,
495 .targinfo = t->data,
496 .hook_mask = e->comefrom,
497 .family = NFPROTO_ARP,
498 };
499
500 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
501 if (ret < 0) {
502 duprintf("arp_tables: check failed for `%s'.\n",
503 t->u.kernel.target->name);
504 return ret;
505 }
506 return 0;
507 }
508
509 static inline int
510 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
511 {
512 struct xt_entry_target *t;
513 struct xt_target *target;
514 int ret;
515
516 ret = check_entry(e, name);
517 if (ret)
518 return ret;
519
520 t = arpt_get_target(e);
521 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
522 t->u.user.revision);
523 if (IS_ERR(target)) {
524 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
525 ret = PTR_ERR(target);
526 goto out;
527 }
528 t->u.kernel.target = target;
529
530 ret = check_target(e, name);
531 if (ret)
532 goto err;
533 return 0;
534 err:
535 module_put(t->u.kernel.target->me);
536 out:
537 return ret;
538 }
539
540 static bool check_underflow(const struct arpt_entry *e)
541 {
542 const struct xt_entry_target *t;
543 unsigned int verdict;
544
545 if (!unconditional(&e->arp))
546 return false;
547 t = arpt_get_target_c(e);
548 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
549 return false;
550 verdict = ((struct xt_standard_target *)t)->verdict;
551 verdict = -verdict - 1;
552 return verdict == NF_DROP || verdict == NF_ACCEPT;
553 }
554
555 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
556 struct xt_table_info *newinfo,
557 const unsigned char *base,
558 const unsigned char *limit,
559 const unsigned int *hook_entries,
560 const unsigned int *underflows,
561 unsigned int valid_hooks)
562 {
563 unsigned int h;
564
565 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
566 (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
567 duprintf("Bad offset %p\n", e);
568 return -EINVAL;
569 }
570
571 if (e->next_offset
572 < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) {
573 duprintf("checking: element %p size %u\n",
574 e, e->next_offset);
575 return -EINVAL;
576 }
577
578 /* Check hooks & underflows */
579 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
580 if (!(valid_hooks & (1 << h)))
581 continue;
582 if ((unsigned char *)e - base == hook_entries[h])
583 newinfo->hook_entry[h] = hook_entries[h];
584 if ((unsigned char *)e - base == underflows[h]) {
585 if (!check_underflow(e)) {
586 pr_err("Underflows must be unconditional and "
587 "use the STANDARD target with "
588 "ACCEPT/DROP\n");
589 return -EINVAL;
590 }
591 newinfo->underflow[h] = underflows[h];
592 }
593 }
594
595 /* Clear counters and comefrom */
596 e->counters = ((struct xt_counters) { 0, 0 });
597 e->comefrom = 0;
598 return 0;
599 }
600
601 static inline void cleanup_entry(struct arpt_entry *e)
602 {
603 struct xt_tgdtor_param par;
604 struct xt_entry_target *t;
605
606 t = arpt_get_target(e);
607 par.target = t->u.kernel.target;
608 par.targinfo = t->data;
609 par.family = NFPROTO_ARP;
610 if (par.target->destroy != NULL)
611 par.target->destroy(&par);
612 module_put(par.target->me);
613 }
614
615 /* Checks and translates the user-supplied table segment (held in
616 * newinfo).
617 */
618 static int translate_table(struct xt_table_info *newinfo, void *entry0,
619 const struct arpt_replace *repl)
620 {
621 struct arpt_entry *iter;
622 unsigned int i;
623 int ret = 0;
624
625 newinfo->size = repl->size;
626 newinfo->number = repl->num_entries;
627
628 /* Init all hooks to impossible value. */
629 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
630 newinfo->hook_entry[i] = 0xFFFFFFFF;
631 newinfo->underflow[i] = 0xFFFFFFFF;
632 }
633
634 duprintf("translate_table: size %u\n", newinfo->size);
635 i = 0;
636
637 /* Walk through entries, checking offsets. */
638 xt_entry_foreach(iter, entry0, newinfo->size) {
639 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
640 entry0 + repl->size,
641 repl->hook_entry,
642 repl->underflow,
643 repl->valid_hooks);
644 if (ret != 0)
645 break;
646 ++i;
647 if (strcmp(arpt_get_target(iter)->u.user.name,
648 XT_ERROR_TARGET) == 0)
649 ++newinfo->stacksize;
650 }
651 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
652 if (ret != 0)
653 return ret;
654
655 if (i != repl->num_entries) {
656 duprintf("translate_table: %u not %u entries\n",
657 i, repl->num_entries);
658 return -EINVAL;
659 }
660
661 /* Check hooks all assigned */
662 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
663 /* Only hooks which are valid */
664 if (!(repl->valid_hooks & (1 << i)))
665 continue;
666 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
667 duprintf("Invalid hook entry %u %u\n",
668 i, repl->hook_entry[i]);
669 return -EINVAL;
670 }
671 if (newinfo->underflow[i] == 0xFFFFFFFF) {
672 duprintf("Invalid underflow %u %u\n",
673 i, repl->underflow[i]);
674 return -EINVAL;
675 }
676 }
677
678 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
679 duprintf("Looping hook\n");
680 return -ELOOP;
681 }
682
683 /* Finally, each sanity check must pass */
684 i = 0;
685 xt_entry_foreach(iter, entry0, newinfo->size) {
686 ret = find_check_entry(iter, repl->name, repl->size);
687 if (ret != 0)
688 break;
689 ++i;
690 }
691
692 if (ret != 0) {
693 xt_entry_foreach(iter, entry0, newinfo->size) {
694 if (i-- == 0)
695 break;
696 cleanup_entry(iter);
697 }
698 return ret;
699 }
700
701 /* And one copy for every other CPU */
702 for_each_possible_cpu(i) {
703 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
704 memcpy(newinfo->entries[i], entry0, newinfo->size);
705 }
706
707 return ret;
708 }
709
710 static void get_counters(const struct xt_table_info *t,
711 struct xt_counters counters[])
712 {
713 struct arpt_entry *iter;
714 unsigned int cpu;
715 unsigned int i;
716
717 for_each_possible_cpu(cpu) {
718 seqcount_t *s = &per_cpu(xt_recseq, cpu);
719
720 i = 0;
721 xt_entry_foreach(iter, t->entries[cpu], t->size) {
722 u64 bcnt, pcnt;
723 unsigned int start;
724
725 do {
726 start = read_seqcount_begin(s);
727 bcnt = iter->counters.bcnt;
728 pcnt = iter->counters.pcnt;
729 } while (read_seqcount_retry(s, start));
730
731 ADD_COUNTER(counters[i], bcnt, pcnt);
732 ++i;
733 }
734 }
735 }
736
737 static struct xt_counters *alloc_counters(const struct xt_table *table)
738 {
739 unsigned int countersize;
740 struct xt_counters *counters;
741 const struct xt_table_info *private = table->private;
742
743 /* We need atomic snapshot of counters: rest doesn't change
744 * (other than comefrom, which userspace doesn't care
745 * about).
746 */
747 countersize = sizeof(struct xt_counters) * private->number;
748 counters = vzalloc(countersize);
749
750 if (counters == NULL)
751 return ERR_PTR(-ENOMEM);
752
753 get_counters(private, counters);
754
755 return counters;
756 }
757
758 static int copy_entries_to_user(unsigned int total_size,
759 const struct xt_table *table,
760 void __user *userptr)
761 {
762 unsigned int off, num;
763 const struct arpt_entry *e;
764 struct xt_counters *counters;
765 struct xt_table_info *private = table->private;
766 int ret = 0;
767 void *loc_cpu_entry;
768
769 counters = alloc_counters(table);
770 if (IS_ERR(counters))
771 return PTR_ERR(counters);
772
773 loc_cpu_entry = private->entries[raw_smp_processor_id()];
774 /* ... then copy entire thing ... */
775 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
776 ret = -EFAULT;
777 goto free_counters;
778 }
779
780 /* FIXME: use iterator macros --RR */
781 /* ... then go back and fix counters and names */
782 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
783 const struct xt_entry_target *t;
784
785 e = (struct arpt_entry *)(loc_cpu_entry + off);
786 if (copy_to_user(userptr + off
787 + offsetof(struct arpt_entry, counters),
788 &counters[num],
789 sizeof(counters[num])) != 0) {
790 ret = -EFAULT;
791 goto free_counters;
792 }
793
794 t = arpt_get_target_c(e);
795 if (copy_to_user(userptr + off + e->target_offset
796 + offsetof(struct xt_entry_target,
797 u.user.name),
798 t->u.kernel.target->name,
799 strlen(t->u.kernel.target->name)+1) != 0) {
800 ret = -EFAULT;
801 goto free_counters;
802 }
803 }
804
805 free_counters:
806 vfree(counters);
807 return ret;
808 }
809
810 #ifdef CONFIG_COMPAT
811 static void compat_standard_from_user(void *dst, const void *src)
812 {
813 int v = *(compat_int_t *)src;
814
815 if (v > 0)
816 v += xt_compat_calc_jump(NFPROTO_ARP, v);
817 memcpy(dst, &v, sizeof(v));
818 }
819
820 static int compat_standard_to_user(void __user *dst, const void *src)
821 {
822 compat_int_t cv = *(int *)src;
823
824 if (cv > 0)
825 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
826 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
827 }
828
829 static int compat_calc_entry(const struct arpt_entry *e,
830 const struct xt_table_info *info,
831 const void *base, struct xt_table_info *newinfo)
832 {
833 const struct xt_entry_target *t;
834 unsigned int entry_offset;
835 int off, i, ret;
836
837 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
838 entry_offset = (void *)e - base;
839
840 t = arpt_get_target_c(e);
841 off += xt_compat_target_offset(t->u.kernel.target);
842 newinfo->size -= off;
843 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
844 if (ret)
845 return ret;
846
847 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
848 if (info->hook_entry[i] &&
849 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
850 newinfo->hook_entry[i] -= off;
851 if (info->underflow[i] &&
852 (e < (struct arpt_entry *)(base + info->underflow[i])))
853 newinfo->underflow[i] -= off;
854 }
855 return 0;
856 }
857
858 static int compat_table_info(const struct xt_table_info *info,
859 struct xt_table_info *newinfo)
860 {
861 struct arpt_entry *iter;
862 void *loc_cpu_entry;
863 int ret;
864
865 if (!newinfo || !info)
866 return -EINVAL;
867
868 /* we dont care about newinfo->entries[] */
869 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
870 newinfo->initial_entries = 0;
871 loc_cpu_entry = info->entries[raw_smp_processor_id()];
872 xt_compat_init_offsets(NFPROTO_ARP, info->number);
873 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
874 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
875 if (ret != 0)
876 return ret;
877 }
878 return 0;
879 }
880 #endif
881
882 static int get_info(struct net *net, void __user *user,
883 const int *len, int compat)
884 {
885 char name[XT_TABLE_MAXNAMELEN];
886 struct xt_table *t;
887 int ret;
888
889 if (*len != sizeof(struct arpt_getinfo)) {
890 duprintf("length %u != %Zu\n", *len,
891 sizeof(struct arpt_getinfo));
892 return -EINVAL;
893 }
894
895 if (copy_from_user(name, user, sizeof(name)) != 0)
896 return -EFAULT;
897
898 name[XT_TABLE_MAXNAMELEN-1] = '\0';
899 #ifdef CONFIG_COMPAT
900 if (compat)
901 xt_compat_lock(NFPROTO_ARP);
902 #endif
903 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
904 "arptable_%s", name);
905 if (t && !IS_ERR(t)) {
906 struct arpt_getinfo info;
907 const struct xt_table_info *private = t->private;
908 #ifdef CONFIG_COMPAT
909 struct xt_table_info tmp;
910
911 if (compat) {
912 ret = compat_table_info(private, &tmp);
913 xt_compat_flush_offsets(NFPROTO_ARP);
914 private = &tmp;
915 }
916 #endif
917 memset(&info, 0, sizeof(info));
918 info.valid_hooks = t->valid_hooks;
919 memcpy(info.hook_entry, private->hook_entry,
920 sizeof(info.hook_entry));
921 memcpy(info.underflow, private->underflow,
922 sizeof(info.underflow));
923 info.num_entries = private->number;
924 info.size = private->size;
925 strcpy(info.name, name);
926
927 if (copy_to_user(user, &info, *len) != 0)
928 ret = -EFAULT;
929 else
930 ret = 0;
931 xt_table_unlock(t);
932 module_put(t->me);
933 } else
934 ret = t ? PTR_ERR(t) : -ENOENT;
935 #ifdef CONFIG_COMPAT
936 if (compat)
937 xt_compat_unlock(NFPROTO_ARP);
938 #endif
939 return ret;
940 }
941
942 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
943 const int *len)
944 {
945 int ret;
946 struct arpt_get_entries get;
947 struct xt_table *t;
948
949 if (*len < sizeof(get)) {
950 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
951 return -EINVAL;
952 }
953 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
954 return -EFAULT;
955 if (*len != sizeof(struct arpt_get_entries) + get.size) {
956 duprintf("get_entries: %u != %Zu\n", *len,
957 sizeof(struct arpt_get_entries) + get.size);
958 return -EINVAL;
959 }
960
961 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
962 if (t && !IS_ERR(t)) {
963 const struct xt_table_info *private = t->private;
964
965 duprintf("t->private->number = %u\n",
966 private->number);
967 if (get.size == private->size)
968 ret = copy_entries_to_user(private->size,
969 t, uptr->entrytable);
970 else {
971 duprintf("get_entries: I've got %u not %u!\n",
972 private->size, get.size);
973 ret = -EAGAIN;
974 }
975 module_put(t->me);
976 xt_table_unlock(t);
977 } else
978 ret = t ? PTR_ERR(t) : -ENOENT;
979
980 return ret;
981 }
982
983 static int __do_replace(struct net *net, const char *name,
984 unsigned int valid_hooks,
985 struct xt_table_info *newinfo,
986 unsigned int num_counters,
987 void __user *counters_ptr)
988 {
989 int ret;
990 struct xt_table *t;
991 struct xt_table_info *oldinfo;
992 struct xt_counters *counters;
993 void *loc_cpu_old_entry;
994 struct arpt_entry *iter;
995
996 ret = 0;
997 counters = vzalloc(num_counters * sizeof(struct xt_counters));
998 if (!counters) {
999 ret = -ENOMEM;
1000 goto out;
1001 }
1002
1003 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1004 "arptable_%s", name);
1005 if (!t || IS_ERR(t)) {
1006 ret = t ? PTR_ERR(t) : -ENOENT;
1007 goto free_newinfo_counters_untrans;
1008 }
1009
1010 /* You lied! */
1011 if (valid_hooks != t->valid_hooks) {
1012 duprintf("Valid hook crap: %08X vs %08X\n",
1013 valid_hooks, t->valid_hooks);
1014 ret = -EINVAL;
1015 goto put_module;
1016 }
1017
1018 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1019 if (!oldinfo)
1020 goto put_module;
1021
1022 /* Update module usage count based on number of rules */
1023 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1024 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1025 if ((oldinfo->number > oldinfo->initial_entries) ||
1026 (newinfo->number <= oldinfo->initial_entries))
1027 module_put(t->me);
1028 if ((oldinfo->number > oldinfo->initial_entries) &&
1029 (newinfo->number <= oldinfo->initial_entries))
1030 module_put(t->me);
1031
1032 /* Get the old counters, and synchronize with replace */
1033 get_counters(oldinfo, counters);
1034
1035 /* Decrease module usage counts and free resource */
1036 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1037 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1038 cleanup_entry(iter);
1039
1040 xt_free_table_info(oldinfo);
1041 if (copy_to_user(counters_ptr, counters,
1042 sizeof(struct xt_counters) * num_counters) != 0)
1043 ret = -EFAULT;
1044 vfree(counters);
1045 xt_table_unlock(t);
1046 return ret;
1047
1048 put_module:
1049 module_put(t->me);
1050 xt_table_unlock(t);
1051 free_newinfo_counters_untrans:
1052 vfree(counters);
1053 out:
1054 return ret;
1055 }
1056
1057 static int do_replace(struct net *net, const void __user *user,
1058 unsigned int len)
1059 {
1060 int ret;
1061 struct arpt_replace tmp;
1062 struct xt_table_info *newinfo;
1063 void *loc_cpu_entry;
1064 struct arpt_entry *iter;
1065
1066 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1067 return -EFAULT;
1068
1069 /* overflow check */
1070 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1071 return -ENOMEM;
1072 tmp.name[sizeof(tmp.name)-1] = 0;
1073
1074 newinfo = xt_alloc_table_info(tmp.size);
1075 if (!newinfo)
1076 return -ENOMEM;
1077
1078 /* choose the copy that is on our node/cpu */
1079 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1080 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1081 tmp.size) != 0) {
1082 ret = -EFAULT;
1083 goto free_newinfo;
1084 }
1085
1086 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1087 if (ret != 0)
1088 goto free_newinfo;
1089
1090 duprintf("arp_tables: Translated table\n");
1091
1092 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1093 tmp.num_counters, tmp.counters);
1094 if (ret)
1095 goto free_newinfo_untrans;
1096 return 0;
1097
1098 free_newinfo_untrans:
1099 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1100 cleanup_entry(iter);
1101 free_newinfo:
1102 xt_free_table_info(newinfo);
1103 return ret;
1104 }
1105
1106 static int do_add_counters(struct net *net, const void __user *user,
1107 unsigned int len, int compat)
1108 {
1109 unsigned int i, curcpu;
1110 struct xt_counters_info tmp;
1111 struct xt_counters *paddc;
1112 unsigned int num_counters;
1113 const char *name;
1114 int size;
1115 void *ptmp;
1116 struct xt_table *t;
1117 const struct xt_table_info *private;
1118 int ret = 0;
1119 void *loc_cpu_entry;
1120 struct arpt_entry *iter;
1121 unsigned int addend;
1122 #ifdef CONFIG_COMPAT
1123 struct compat_xt_counters_info compat_tmp;
1124
1125 if (compat) {
1126 ptmp = &compat_tmp;
1127 size = sizeof(struct compat_xt_counters_info);
1128 } else
1129 #endif
1130 {
1131 ptmp = &tmp;
1132 size = sizeof(struct xt_counters_info);
1133 }
1134
1135 if (copy_from_user(ptmp, user, size) != 0)
1136 return -EFAULT;
1137
1138 #ifdef CONFIG_COMPAT
1139 if (compat) {
1140 num_counters = compat_tmp.num_counters;
1141 name = compat_tmp.name;
1142 } else
1143 #endif
1144 {
1145 num_counters = tmp.num_counters;
1146 name = tmp.name;
1147 }
1148
1149 if (len != size + num_counters * sizeof(struct xt_counters))
1150 return -EINVAL;
1151
1152 paddc = vmalloc(len - size);
1153 if (!paddc)
1154 return -ENOMEM;
1155
1156 if (copy_from_user(paddc, user + size, len - size) != 0) {
1157 ret = -EFAULT;
1158 goto free;
1159 }
1160
1161 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1162 if (!t || IS_ERR(t)) {
1163 ret = t ? PTR_ERR(t) : -ENOENT;
1164 goto free;
1165 }
1166
1167 local_bh_disable();
1168 private = t->private;
1169 if (private->number != num_counters) {
1170 ret = -EINVAL;
1171 goto unlock_up_free;
1172 }
1173
1174 i = 0;
1175 /* Choose the copy that is on our node */
1176 curcpu = smp_processor_id();
1177 loc_cpu_entry = private->entries[curcpu];
1178 addend = xt_write_recseq_begin();
1179 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1180 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1181 ++i;
1182 }
1183 xt_write_recseq_end(addend);
1184 unlock_up_free:
1185 local_bh_enable();
1186 xt_table_unlock(t);
1187 module_put(t->me);
1188 free:
1189 vfree(paddc);
1190
1191 return ret;
1192 }
1193
1194 #ifdef CONFIG_COMPAT
1195 static inline void compat_release_entry(struct compat_arpt_entry *e)
1196 {
1197 struct xt_entry_target *t;
1198
1199 t = compat_arpt_get_target(e);
1200 module_put(t->u.kernel.target->me);
1201 }
1202
1203 static inline int
1204 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1205 struct xt_table_info *newinfo,
1206 unsigned int *size,
1207 const unsigned char *base,
1208 const unsigned char *limit,
1209 const unsigned int *hook_entries,
1210 const unsigned int *underflows,
1211 const char *name)
1212 {
1213 struct xt_entry_target *t;
1214 struct xt_target *target;
1215 unsigned int entry_offset;
1216 int ret, off, h;
1217
1218 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1219 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1220 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1221 duprintf("Bad offset %p, limit = %p\n", e, limit);
1222 return -EINVAL;
1223 }
1224
1225 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1226 sizeof(struct compat_xt_entry_target)) {
1227 duprintf("checking: element %p size %u\n",
1228 e, e->next_offset);
1229 return -EINVAL;
1230 }
1231
1232 /* For purposes of check_entry casting the compat entry is fine */
1233 ret = check_entry((struct arpt_entry *)e, name);
1234 if (ret)
1235 return ret;
1236
1237 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1238 entry_offset = (void *)e - (void *)base;
1239
1240 t = compat_arpt_get_target(e);
1241 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1242 t->u.user.revision);
1243 if (IS_ERR(target)) {
1244 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1245 t->u.user.name);
1246 ret = PTR_ERR(target);
1247 goto out;
1248 }
1249 t->u.kernel.target = target;
1250
1251 off += xt_compat_target_offset(target);
1252 *size += off;
1253 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1254 if (ret)
1255 goto release_target;
1256
1257 /* Check hooks & underflows */
1258 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1259 if ((unsigned char *)e - base == hook_entries[h])
1260 newinfo->hook_entry[h] = hook_entries[h];
1261 if ((unsigned char *)e - base == underflows[h])
1262 newinfo->underflow[h] = underflows[h];
1263 }
1264
1265 /* Clear counters and comefrom */
1266 memset(&e->counters, 0, sizeof(e->counters));
1267 e->comefrom = 0;
1268 return 0;
1269
1270 release_target:
1271 module_put(t->u.kernel.target->me);
1272 out:
1273 return ret;
1274 }
1275
1276 static int
1277 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1278 unsigned int *size, const char *name,
1279 struct xt_table_info *newinfo, unsigned char *base)
1280 {
1281 struct xt_entry_target *t;
1282 struct xt_target *target;
1283 struct arpt_entry *de;
1284 unsigned int origsize;
1285 int ret, h;
1286
1287 ret = 0;
1288 origsize = *size;
1289 de = (struct arpt_entry *)*dstptr;
1290 memcpy(de, e, sizeof(struct arpt_entry));
1291 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1292
1293 *dstptr += sizeof(struct arpt_entry);
1294 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1295
1296 de->target_offset = e->target_offset - (origsize - *size);
1297 t = compat_arpt_get_target(e);
1298 target = t->u.kernel.target;
1299 xt_compat_target_from_user(t, dstptr, size);
1300
1301 de->next_offset = e->next_offset - (origsize - *size);
1302 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1303 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1304 newinfo->hook_entry[h] -= origsize - *size;
1305 if ((unsigned char *)de - base < newinfo->underflow[h])
1306 newinfo->underflow[h] -= origsize - *size;
1307 }
1308 return ret;
1309 }
1310
1311 static int translate_compat_table(const char *name,
1312 unsigned int valid_hooks,
1313 struct xt_table_info **pinfo,
1314 void **pentry0,
1315 unsigned int total_size,
1316 unsigned int number,
1317 unsigned int *hook_entries,
1318 unsigned int *underflows)
1319 {
1320 unsigned int i, j;
1321 struct xt_table_info *newinfo, *info;
1322 void *pos, *entry0, *entry1;
1323 struct compat_arpt_entry *iter0;
1324 struct arpt_entry *iter1;
1325 unsigned int size;
1326 int ret = 0;
1327
1328 info = *pinfo;
1329 entry0 = *pentry0;
1330 size = total_size;
1331 info->number = number;
1332
1333 /* Init all hooks to impossible value. */
1334 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1335 info->hook_entry[i] = 0xFFFFFFFF;
1336 info->underflow[i] = 0xFFFFFFFF;
1337 }
1338
1339 duprintf("translate_compat_table: size %u\n", info->size);
1340 j = 0;
1341 xt_compat_lock(NFPROTO_ARP);
1342 xt_compat_init_offsets(NFPROTO_ARP, number);
1343 /* Walk through entries, checking offsets. */
1344 xt_entry_foreach(iter0, entry0, total_size) {
1345 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1346 entry0,
1347 entry0 + total_size,
1348 hook_entries,
1349 underflows,
1350 name);
1351 if (ret != 0)
1352 goto out_unlock;
1353 ++j;
1354 }
1355
1356 ret = -EINVAL;
1357 if (j != number) {
1358 duprintf("translate_compat_table: %u not %u entries\n",
1359 j, number);
1360 goto out_unlock;
1361 }
1362
1363 /* Check hooks all assigned */
1364 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1365 /* Only hooks which are valid */
1366 if (!(valid_hooks & (1 << i)))
1367 continue;
1368 if (info->hook_entry[i] == 0xFFFFFFFF) {
1369 duprintf("Invalid hook entry %u %u\n",
1370 i, hook_entries[i]);
1371 goto out_unlock;
1372 }
1373 if (info->underflow[i] == 0xFFFFFFFF) {
1374 duprintf("Invalid underflow %u %u\n",
1375 i, underflows[i]);
1376 goto out_unlock;
1377 }
1378 }
1379
1380 ret = -ENOMEM;
1381 newinfo = xt_alloc_table_info(size);
1382 if (!newinfo)
1383 goto out_unlock;
1384
1385 newinfo->number = number;
1386 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1387 newinfo->hook_entry[i] = info->hook_entry[i];
1388 newinfo->underflow[i] = info->underflow[i];
1389 }
1390 entry1 = newinfo->entries[raw_smp_processor_id()];
1391 pos = entry1;
1392 size = total_size;
1393 xt_entry_foreach(iter0, entry0, total_size) {
1394 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1395 name, newinfo, entry1);
1396 if (ret != 0)
1397 break;
1398 }
1399 xt_compat_flush_offsets(NFPROTO_ARP);
1400 xt_compat_unlock(NFPROTO_ARP);
1401 if (ret)
1402 goto free_newinfo;
1403
1404 ret = -ELOOP;
1405 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1406 goto free_newinfo;
1407
1408 i = 0;
1409 xt_entry_foreach(iter1, entry1, newinfo->size) {
1410 ret = check_target(iter1, name);
1411 if (ret != 0)
1412 break;
1413 ++i;
1414 if (strcmp(arpt_get_target(iter1)->u.user.name,
1415 XT_ERROR_TARGET) == 0)
1416 ++newinfo->stacksize;
1417 }
1418 if (ret) {
1419 /*
1420 * The first i matches need cleanup_entry (calls ->destroy)
1421 * because they had called ->check already. The other j-i
1422 * entries need only release.
1423 */
1424 int skip = i;
1425 j -= i;
1426 xt_entry_foreach(iter0, entry0, newinfo->size) {
1427 if (skip-- > 0)
1428 continue;
1429 if (j-- == 0)
1430 break;
1431 compat_release_entry(iter0);
1432 }
1433 xt_entry_foreach(iter1, entry1, newinfo->size) {
1434 if (i-- == 0)
1435 break;
1436 cleanup_entry(iter1);
1437 }
1438 xt_free_table_info(newinfo);
1439 return ret;
1440 }
1441
1442 /* And one copy for every other CPU */
1443 for_each_possible_cpu(i)
1444 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1445 memcpy(newinfo->entries[i], entry1, newinfo->size);
1446
1447 *pinfo = newinfo;
1448 *pentry0 = entry1;
1449 xt_free_table_info(info);
1450 return 0;
1451
1452 free_newinfo:
1453 xt_free_table_info(newinfo);
1454 out:
1455 xt_entry_foreach(iter0, entry0, total_size) {
1456 if (j-- == 0)
1457 break;
1458 compat_release_entry(iter0);
1459 }
1460 return ret;
1461 out_unlock:
1462 xt_compat_flush_offsets(NFPROTO_ARP);
1463 xt_compat_unlock(NFPROTO_ARP);
1464 goto out;
1465 }
1466
1467 struct compat_arpt_replace {
1468 char name[XT_TABLE_MAXNAMELEN];
1469 u32 valid_hooks;
1470 u32 num_entries;
1471 u32 size;
1472 u32 hook_entry[NF_ARP_NUMHOOKS];
1473 u32 underflow[NF_ARP_NUMHOOKS];
1474 u32 num_counters;
1475 compat_uptr_t counters;
1476 struct compat_arpt_entry entries[0];
1477 };
1478
1479 static int compat_do_replace(struct net *net, void __user *user,
1480 unsigned int len)
1481 {
1482 int ret;
1483 struct compat_arpt_replace tmp;
1484 struct xt_table_info *newinfo;
1485 void *loc_cpu_entry;
1486 struct arpt_entry *iter;
1487
1488 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1489 return -EFAULT;
1490
1491 /* overflow check */
1492 if (tmp.size >= INT_MAX / num_possible_cpus())
1493 return -ENOMEM;
1494 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1495 return -ENOMEM;
1496 tmp.name[sizeof(tmp.name)-1] = 0;
1497
1498 newinfo = xt_alloc_table_info(tmp.size);
1499 if (!newinfo)
1500 return -ENOMEM;
1501
1502 /* choose the copy that is on our node/cpu */
1503 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1504 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1505 ret = -EFAULT;
1506 goto free_newinfo;
1507 }
1508
1509 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1510 &newinfo, &loc_cpu_entry, tmp.size,
1511 tmp.num_entries, tmp.hook_entry,
1512 tmp.underflow);
1513 if (ret != 0)
1514 goto free_newinfo;
1515
1516 duprintf("compat_do_replace: Translated table\n");
1517
1518 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1519 tmp.num_counters, compat_ptr(tmp.counters));
1520 if (ret)
1521 goto free_newinfo_untrans;
1522 return 0;
1523
1524 free_newinfo_untrans:
1525 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1526 cleanup_entry(iter);
1527 free_newinfo:
1528 xt_free_table_info(newinfo);
1529 return ret;
1530 }
1531
1532 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1533 unsigned int len)
1534 {
1535 int ret;
1536
1537 if (!capable(CAP_NET_ADMIN))
1538 return -EPERM;
1539
1540 switch (cmd) {
1541 case ARPT_SO_SET_REPLACE:
1542 ret = compat_do_replace(sock_net(sk), user, len);
1543 break;
1544
1545 case ARPT_SO_SET_ADD_COUNTERS:
1546 ret = do_add_counters(sock_net(sk), user, len, 1);
1547 break;
1548
1549 default:
1550 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1551 ret = -EINVAL;
1552 }
1553
1554 return ret;
1555 }
1556
1557 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1558 compat_uint_t *size,
1559 struct xt_counters *counters,
1560 unsigned int i)
1561 {
1562 struct xt_entry_target *t;
1563 struct compat_arpt_entry __user *ce;
1564 u_int16_t target_offset, next_offset;
1565 compat_uint_t origsize;
1566 int ret;
1567
1568 origsize = *size;
1569 ce = (struct compat_arpt_entry __user *)*dstptr;
1570 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1571 copy_to_user(&ce->counters, &counters[i],
1572 sizeof(counters[i])) != 0)
1573 return -EFAULT;
1574
1575 *dstptr += sizeof(struct compat_arpt_entry);
1576 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1577
1578 target_offset = e->target_offset - (origsize - *size);
1579
1580 t = arpt_get_target(e);
1581 ret = xt_compat_target_to_user(t, dstptr, size);
1582 if (ret)
1583 return ret;
1584 next_offset = e->next_offset - (origsize - *size);
1585 if (put_user(target_offset, &ce->target_offset) != 0 ||
1586 put_user(next_offset, &ce->next_offset) != 0)
1587 return -EFAULT;
1588 return 0;
1589 }
1590
1591 static int compat_copy_entries_to_user(unsigned int total_size,
1592 struct xt_table *table,
1593 void __user *userptr)
1594 {
1595 struct xt_counters *counters;
1596 const struct xt_table_info *private = table->private;
1597 void __user *pos;
1598 unsigned int size;
1599 int ret = 0;
1600 void *loc_cpu_entry;
1601 unsigned int i = 0;
1602 struct arpt_entry *iter;
1603
1604 counters = alloc_counters(table);
1605 if (IS_ERR(counters))
1606 return PTR_ERR(counters);
1607
1608 /* choose the copy on our node/cpu */
1609 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1610 pos = userptr;
1611 size = total_size;
1612 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1613 ret = compat_copy_entry_to_user(iter, &pos,
1614 &size, counters, i++);
1615 if (ret != 0)
1616 break;
1617 }
1618 vfree(counters);
1619 return ret;
1620 }
1621
1622 struct compat_arpt_get_entries {
1623 char name[XT_TABLE_MAXNAMELEN];
1624 compat_uint_t size;
1625 struct compat_arpt_entry entrytable[0];
1626 };
1627
1628 static int compat_get_entries(struct net *net,
1629 struct compat_arpt_get_entries __user *uptr,
1630 int *len)
1631 {
1632 int ret;
1633 struct compat_arpt_get_entries get;
1634 struct xt_table *t;
1635
1636 if (*len < sizeof(get)) {
1637 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1638 return -EINVAL;
1639 }
1640 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1641 return -EFAULT;
1642 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1643 duprintf("compat_get_entries: %u != %zu\n",
1644 *len, sizeof(get) + get.size);
1645 return -EINVAL;
1646 }
1647
1648 xt_compat_lock(NFPROTO_ARP);
1649 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1650 if (t && !IS_ERR(t)) {
1651 const struct xt_table_info *private = t->private;
1652 struct xt_table_info info;
1653
1654 duprintf("t->private->number = %u\n", private->number);
1655 ret = compat_table_info(private, &info);
1656 if (!ret && get.size == info.size) {
1657 ret = compat_copy_entries_to_user(private->size,
1658 t, uptr->entrytable);
1659 } else if (!ret) {
1660 duprintf("compat_get_entries: I've got %u not %u!\n",
1661 private->size, get.size);
1662 ret = -EAGAIN;
1663 }
1664 xt_compat_flush_offsets(NFPROTO_ARP);
1665 module_put(t->me);
1666 xt_table_unlock(t);
1667 } else
1668 ret = t ? PTR_ERR(t) : -ENOENT;
1669
1670 xt_compat_unlock(NFPROTO_ARP);
1671 return ret;
1672 }
1673
1674 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1675
1676 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1677 int *len)
1678 {
1679 int ret;
1680
1681 if (!capable(CAP_NET_ADMIN))
1682 return -EPERM;
1683
1684 switch (cmd) {
1685 case ARPT_SO_GET_INFO:
1686 ret = get_info(sock_net(sk), user, len, 1);
1687 break;
1688 case ARPT_SO_GET_ENTRIES:
1689 ret = compat_get_entries(sock_net(sk), user, len);
1690 break;
1691 default:
1692 ret = do_arpt_get_ctl(sk, cmd, user, len);
1693 }
1694 return ret;
1695 }
1696 #endif
1697
1698 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1699 {
1700 int ret;
1701
1702 if (!capable(CAP_NET_ADMIN))
1703 return -EPERM;
1704
1705 switch (cmd) {
1706 case ARPT_SO_SET_REPLACE:
1707 ret = do_replace(sock_net(sk), user, len);
1708 break;
1709
1710 case ARPT_SO_SET_ADD_COUNTERS:
1711 ret = do_add_counters(sock_net(sk), user, len, 0);
1712 break;
1713
1714 default:
1715 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1716 ret = -EINVAL;
1717 }
1718
1719 return ret;
1720 }
1721
1722 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1723 {
1724 int ret;
1725
1726 if (!capable(CAP_NET_ADMIN))
1727 return -EPERM;
1728
1729 switch (cmd) {
1730 case ARPT_SO_GET_INFO:
1731 ret = get_info(sock_net(sk), user, len, 0);
1732 break;
1733
1734 case ARPT_SO_GET_ENTRIES:
1735 ret = get_entries(sock_net(sk), user, len);
1736 break;
1737
1738 case ARPT_SO_GET_REVISION_TARGET: {
1739 struct xt_get_revision rev;
1740
1741 if (*len != sizeof(rev)) {
1742 ret = -EINVAL;
1743 break;
1744 }
1745 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1746 ret = -EFAULT;
1747 break;
1748 }
1749 rev.name[sizeof(rev.name)-1] = 0;
1750
1751 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1752 rev.revision, 1, &ret),
1753 "arpt_%s", rev.name);
1754 break;
1755 }
1756
1757 default:
1758 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1759 ret = -EINVAL;
1760 }
1761
1762 return ret;
1763 }
1764
1765 struct xt_table *arpt_register_table(struct net *net,
1766 const struct xt_table *table,
1767 const struct arpt_replace *repl)
1768 {
1769 int ret;
1770 struct xt_table_info *newinfo;
1771 struct xt_table_info bootstrap = {0};
1772 void *loc_cpu_entry;
1773 struct xt_table *new_table;
1774
1775 newinfo = xt_alloc_table_info(repl->size);
1776 if (!newinfo) {
1777 ret = -ENOMEM;
1778 goto out;
1779 }
1780
1781 /* choose the copy on our node/cpu */
1782 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1783 memcpy(loc_cpu_entry, repl->entries, repl->size);
1784
1785 ret = translate_table(newinfo, loc_cpu_entry, repl);
1786 duprintf("arpt_register_table: translate table gives %d\n", ret);
1787 if (ret != 0)
1788 goto out_free;
1789
1790 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1791 if (IS_ERR(new_table)) {
1792 ret = PTR_ERR(new_table);
1793 goto out_free;
1794 }
1795 return new_table;
1796
1797 out_free:
1798 xt_free_table_info(newinfo);
1799 out:
1800 return ERR_PTR(ret);
1801 }
1802
1803 void arpt_unregister_table(struct xt_table *table)
1804 {
1805 struct xt_table_info *private;
1806 void *loc_cpu_entry;
1807 struct module *table_owner = table->me;
1808 struct arpt_entry *iter;
1809
1810 private = xt_unregister_table(table);
1811
1812 /* Decrease module usage counts and free resources */
1813 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1814 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1815 cleanup_entry(iter);
1816 if (private->number > private->initial_entries)
1817 module_put(table_owner);
1818 xt_free_table_info(private);
1819 }
1820
1821 /* The built-in targets: standard (NULL) and error. */
1822 static struct xt_target arpt_builtin_tg[] __read_mostly = {
1823 {
1824 .name = XT_STANDARD_TARGET,
1825 .targetsize = sizeof(int),
1826 .family = NFPROTO_ARP,
1827 #ifdef CONFIG_COMPAT
1828 .compatsize = sizeof(compat_int_t),
1829 .compat_from_user = compat_standard_from_user,
1830 .compat_to_user = compat_standard_to_user,
1831 #endif
1832 },
1833 {
1834 .name = XT_ERROR_TARGET,
1835 .target = arpt_error,
1836 .targetsize = XT_FUNCTION_MAXNAMELEN,
1837 .family = NFPROTO_ARP,
1838 },
1839 };
1840
1841 static struct nf_sockopt_ops arpt_sockopts = {
1842 .pf = PF_INET,
1843 .set_optmin = ARPT_BASE_CTL,
1844 .set_optmax = ARPT_SO_SET_MAX+1,
1845 .set = do_arpt_set_ctl,
1846 #ifdef CONFIG_COMPAT
1847 .compat_set = compat_do_arpt_set_ctl,
1848 #endif
1849 .get_optmin = ARPT_BASE_CTL,
1850 .get_optmax = ARPT_SO_GET_MAX+1,
1851 .get = do_arpt_get_ctl,
1852 #ifdef CONFIG_COMPAT
1853 .compat_get = compat_do_arpt_get_ctl,
1854 #endif
1855 .owner = THIS_MODULE,
1856 };
1857
1858 static int __net_init arp_tables_net_init(struct net *net)
1859 {
1860 return xt_proto_init(net, NFPROTO_ARP);
1861 }
1862
1863 static void __net_exit arp_tables_net_exit(struct net *net)
1864 {
1865 xt_proto_fini(net, NFPROTO_ARP);
1866 }
1867
1868 static struct pernet_operations arp_tables_net_ops = {
1869 .init = arp_tables_net_init,
1870 .exit = arp_tables_net_exit,
1871 };
1872
1873 static int __init arp_tables_init(void)
1874 {
1875 int ret;
1876
1877 ret = register_pernet_subsys(&arp_tables_net_ops);
1878 if (ret < 0)
1879 goto err1;
1880
1881 /* No one else will be downing sem now, so we won't sleep */
1882 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1883 if (ret < 0)
1884 goto err2;
1885
1886 /* Register setsockopt */
1887 ret = nf_register_sockopt(&arpt_sockopts);
1888 if (ret < 0)
1889 goto err4;
1890
1891 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1892 return 0;
1893
1894 err4:
1895 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1896 err2:
1897 unregister_pernet_subsys(&arp_tables_net_ops);
1898 err1:
1899 return ret;
1900 }
1901
1902 static void __exit arp_tables_fini(void)
1903 {
1904 nf_unregister_sockopt(&arpt_sockopts);
1905 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1906 unregister_pernet_subsys(&arp_tables_net_ops);
1907 }
1908
1909 EXPORT_SYMBOL(arpt_register_table);
1910 EXPORT_SYMBOL(arpt_unregister_table);
1911 EXPORT_SYMBOL(arpt_do_table);
1912
1913 module_init(arp_tables_init);
1914 module_exit(arp_tables_fini);