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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
32MODULE_LICENSE("GPL");
33MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
34MODULE_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
57void *arpt_alloc_initial_table(const struct xt_table *info)
58{
59 return xt_alloc_initial_table(arpt, ARPT);
60}
61EXPORT_SYMBOL_GPL(arpt_alloc_initial_table);
62
63static 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 */
83static 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. */
101static 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
205static 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
221static unsigned int
222arpt_error(struct sk_buff *skb, const struct xt_action_param *par)
223{
224 net_err_ratelimited("arp_tables: error: '%s'\n",
225 (const char *)par->targinfo);
226
227 return NF_DROP;
228}
229
230static inline const struct xt_entry_target *
231arpt_get_target_c(const struct arpt_entry *e)
232{
233 return arpt_get_target((struct arpt_entry *)e);
234}
235
236static inline struct arpt_entry *
237get_entry(const void *base, unsigned int offset)
238{
239 return (struct arpt_entry *)(base + offset);
240}
241
242static inline __pure
243struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry)
244{
245 return (void *)entry + entry->next_offset;
246}
247
248unsigned int arpt_do_table(struct sk_buff *skb,
249 unsigned int hook,
250 const struct net_device *in,
251 const struct net_device *out,
252 struct xt_table *table)
253{
254 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
255 unsigned int verdict = NF_DROP;
256 const struct arphdr *arp;
257 struct arpt_entry *e, *back;
258 const char *indev, *outdev;
259 void *table_base;
260 const struct xt_table_info *private;
261 struct xt_action_param acpar;
262 unsigned int addend;
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 local_bh_disable();
271 addend = xt_write_recseq_begin();
272 private = table->private;
273 table_base = private->entries[smp_processor_id()];
274
275 e = get_entry(table_base, private->hook_entry[hook]);
276 back = get_entry(table_base, private->underflow[hook]);
277
278 acpar.in = in;
279 acpar.out = out;
280 acpar.hooknum = hook;
281 acpar.family = NFPROTO_ARP;
282 acpar.hotdrop = false;
283
284 arp = arp_hdr(skb);
285 do {
286 const struct xt_entry_target *t;
287
288 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
289 e = arpt_next_entry(e);
290 continue;
291 }
292
293 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
294
295 t = arpt_get_target_c(e);
296
297 /* Standard target? */
298 if (!t->u.kernel.target->target) {
299 int v;
300
301 v = ((struct xt_standard_target *)t)->verdict;
302 if (v < 0) {
303 /* Pop from stack? */
304 if (v != XT_RETURN) {
305 verdict = (unsigned int)(-v) - 1;
306 break;
307 }
308 e = back;
309 back = get_entry(table_base, back->comefrom);
310 continue;
311 }
312 if (table_base + v
313 != arpt_next_entry(e)) {
314 /* Save old back ptr in next entry */
315 struct arpt_entry *next = arpt_next_entry(e);
316 next->comefrom = (void *)back - table_base;
317
318 /* set back pointer to next entry */
319 back = next;
320 }
321
322 e = get_entry(table_base, v);
323 continue;
324 }
325
326 /* Targets which reenter must return
327 * abs. verdicts
328 */
329 acpar.target = t->u.kernel.target;
330 acpar.targinfo = t->data;
331 verdict = t->u.kernel.target->target(skb, &acpar);
332
333 /* Target might have changed stuff. */
334 arp = arp_hdr(skb);
335
336 if (verdict == XT_CONTINUE)
337 e = arpt_next_entry(e);
338 else
339 /* Verdict */
340 break;
341 } while (!acpar.hotdrop);
342 xt_write_recseq_end(addend);
343 local_bh_enable();
344
345 if (acpar.hotdrop)
346 return NF_DROP;
347 else
348 return verdict;
349}
350
351/* All zeroes == unconditional rule. */
352static inline bool unconditional(const struct arpt_arp *arp)
353{
354 static const struct arpt_arp uncond;
355
356 return memcmp(arp, &uncond, sizeof(uncond)) == 0;
357}
358
359/* Figures out from what hook each rule can be called: returns 0 if
360 * there are loops. Puts hook bitmask in comefrom.
361 */
362static int mark_source_chains(const struct xt_table_info *newinfo,
363 unsigned int valid_hooks, void *entry0)
364{
365 unsigned int hook;
366
367 /* No recursion; use packet counter to save back ptrs (reset
368 * to 0 as we leave), and comefrom to save source hook bitmask.
369 */
370 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
371 unsigned int pos = newinfo->hook_entry[hook];
372 struct arpt_entry *e
373 = (struct arpt_entry *)(entry0 + pos);
374
375 if (!(valid_hooks & (1 << hook)))
376 continue;
377
378 /* Set initial back pointer. */
379 e->counters.pcnt = pos;
380
381 for (;;) {
382 const struct xt_standard_target *t
383 = (void *)arpt_get_target_c(e);
384 int visited = e->comefrom & (1 << hook);
385
386 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
387 pr_notice("arptables: loop hook %u pos %u %08X.\n",
388 hook, pos, e->comefrom);
389 return 0;
390 }
391 e->comefrom
392 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
393
394 /* Unconditional return/END. */
395 if ((e->target_offset == sizeof(struct arpt_entry) &&
396 (strcmp(t->target.u.user.name,
397 XT_STANDARD_TARGET) == 0) &&
398 t->verdict < 0 && unconditional(&e->arp)) ||
399 visited) {
400 unsigned int oldpos, size;
401
402 if ((strcmp(t->target.u.user.name,
403 XT_STANDARD_TARGET) == 0) &&
404 t->verdict < -NF_MAX_VERDICT - 1) {
405 duprintf("mark_source_chains: bad "
406 "negative verdict (%i)\n",
407 t->verdict);
408 return 0;
409 }
410
411 /* Return: backtrack through the last
412 * big jump.
413 */
414 do {
415 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
416 oldpos = pos;
417 pos = e->counters.pcnt;
418 e->counters.pcnt = 0;
419
420 /* We're at the start. */
421 if (pos == oldpos)
422 goto next;
423
424 e = (struct arpt_entry *)
425 (entry0 + pos);
426 } while (oldpos == pos + e->next_offset);
427
428 /* Move along one */
429 size = e->next_offset;
430 e = (struct arpt_entry *)
431 (entry0 + pos + size);
432 e->counters.pcnt = pos;
433 pos += size;
434 } else {
435 int newpos = t->verdict;
436
437 if (strcmp(t->target.u.user.name,
438 XT_STANDARD_TARGET) == 0 &&
439 newpos >= 0) {
440 if (newpos > newinfo->size -
441 sizeof(struct arpt_entry)) {
442 duprintf("mark_source_chains: "
443 "bad verdict (%i)\n",
444 newpos);
445 return 0;
446 }
447
448 /* This a jump; chase it. */
449 duprintf("Jump rule %u -> %u\n",
450 pos, newpos);
451 } else {
452 /* ... this is a fallthru */
453 newpos = pos + e->next_offset;
454 }
455 e = (struct arpt_entry *)
456 (entry0 + newpos);
457 e->counters.pcnt = pos;
458 pos = newpos;
459 }
460 }
461 next:
462 duprintf("Finished chain %u\n", hook);
463 }
464 return 1;
465}
466
467static inline int check_entry(const struct arpt_entry *e, const char *name)
468{
469 const struct xt_entry_target *t;
470
471 if (!arp_checkentry(&e->arp)) {
472 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
473 return -EINVAL;
474 }
475
476 if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
477 return -EINVAL;
478
479 t = arpt_get_target_c(e);
480 if (e->target_offset + t->u.target_size > e->next_offset)
481 return -EINVAL;
482
483 return 0;
484}
485
486static inline int check_target(struct arpt_entry *e, const char *name)
487{
488 struct xt_entry_target *t = arpt_get_target(e);
489 int ret;
490 struct xt_tgchk_param par = {
491 .table = name,
492 .entryinfo = e,
493 .target = t->u.kernel.target,
494 .targinfo = t->data,
495 .hook_mask = e->comefrom,
496 .family = NFPROTO_ARP,
497 };
498
499 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
500 if (ret < 0) {
501 duprintf("arp_tables: check failed for `%s'.\n",
502 t->u.kernel.target->name);
503 return ret;
504 }
505 return 0;
506}
507
508static inline int
509find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
510{
511 struct xt_entry_target *t;
512 struct xt_target *target;
513 int ret;
514
515 ret = check_entry(e, name);
516 if (ret)
517 return ret;
518
519 t = arpt_get_target(e);
520 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
521 t->u.user.revision);
522 if (IS_ERR(target)) {
523 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
524 ret = PTR_ERR(target);
525 goto out;
526 }
527 t->u.kernel.target = target;
528
529 ret = check_target(e, name);
530 if (ret)
531 goto err;
532 return 0;
533err:
534 module_put(t->u.kernel.target->me);
535out:
536 return ret;
537}
538
539static bool check_underflow(const struct arpt_entry *e)
540{
541 const struct xt_entry_target *t;
542 unsigned int verdict;
543
544 if (!unconditional(&e->arp))
545 return false;
546 t = arpt_get_target_c(e);
547 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
548 return false;
549 verdict = ((struct xt_standard_target *)t)->verdict;
550 verdict = -verdict - 1;
551 return verdict == NF_DROP || verdict == NF_ACCEPT;
552}
553
554static inline int check_entry_size_and_hooks(struct arpt_entry *e,
555 struct xt_table_info *newinfo,
556 const unsigned char *base,
557 const unsigned char *limit,
558 const unsigned int *hook_entries,
559 const unsigned int *underflows,
560 unsigned int valid_hooks)
561{
562 unsigned int h;
563
564 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
565 (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
566 duprintf("Bad offset %p\n", e);
567 return -EINVAL;
568 }
569
570 if (e->next_offset
571 < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) {
572 duprintf("checking: element %p size %u\n",
573 e, e->next_offset);
574 return -EINVAL;
575 }
576
577 /* Check hooks & underflows */
578 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
579 if (!(valid_hooks & (1 << h)))
580 continue;
581 if ((unsigned char *)e - base == hook_entries[h])
582 newinfo->hook_entry[h] = hook_entries[h];
583 if ((unsigned char *)e - base == underflows[h]) {
584 if (!check_underflow(e)) {
585 pr_err("Underflows must be unconditional and "
586 "use the STANDARD target with "
587 "ACCEPT/DROP\n");
588 return -EINVAL;
589 }
590 newinfo->underflow[h] = underflows[h];
591 }
592 }
593
594 /* Clear counters and comefrom */
595 e->counters = ((struct xt_counters) { 0, 0 });
596 e->comefrom = 0;
597 return 0;
598}
599
600static inline void cleanup_entry(struct arpt_entry *e)
601{
602 struct xt_tgdtor_param par;
603 struct xt_entry_target *t;
604
605 t = arpt_get_target(e);
606 par.target = t->u.kernel.target;
607 par.targinfo = t->data;
608 par.family = NFPROTO_ARP;
609 if (par.target->destroy != NULL)
610 par.target->destroy(&par);
611 module_put(par.target->me);
612}
613
614/* Checks and translates the user-supplied table segment (held in
615 * newinfo).
616 */
617static int translate_table(struct xt_table_info *newinfo, void *entry0,
618 const struct arpt_replace *repl)
619{
620 struct arpt_entry *iter;
621 unsigned int i;
622 int ret = 0;
623
624 newinfo->size = repl->size;
625 newinfo->number = repl->num_entries;
626
627 /* Init all hooks to impossible value. */
628 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
629 newinfo->hook_entry[i] = 0xFFFFFFFF;
630 newinfo->underflow[i] = 0xFFFFFFFF;
631 }
632
633 duprintf("translate_table: size %u\n", newinfo->size);
634 i = 0;
635
636 /* Walk through entries, checking offsets. */
637 xt_entry_foreach(iter, entry0, newinfo->size) {
638 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
639 entry0 + repl->size,
640 repl->hook_entry,
641 repl->underflow,
642 repl->valid_hooks);
643 if (ret != 0)
644 break;
645 ++i;
646 if (strcmp(arpt_get_target(iter)->u.user.name,
647 XT_ERROR_TARGET) == 0)
648 ++newinfo->stacksize;
649 }
650 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
651 if (ret != 0)
652 return ret;
653
654 if (i != repl->num_entries) {
655 duprintf("translate_table: %u not %u entries\n",
656 i, repl->num_entries);
657 return -EINVAL;
658 }
659
660 /* Check hooks all assigned */
661 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
662 /* Only hooks which are valid */
663 if (!(repl->valid_hooks & (1 << i)))
664 continue;
665 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
666 duprintf("Invalid hook entry %u %u\n",
667 i, repl->hook_entry[i]);
668 return -EINVAL;
669 }
670 if (newinfo->underflow[i] == 0xFFFFFFFF) {
671 duprintf("Invalid underflow %u %u\n",
672 i, repl->underflow[i]);
673 return -EINVAL;
674 }
675 }
676
677 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
678 duprintf("Looping hook\n");
679 return -ELOOP;
680 }
681
682 /* Finally, each sanity check must pass */
683 i = 0;
684 xt_entry_foreach(iter, entry0, newinfo->size) {
685 ret = find_check_entry(iter, repl->name, repl->size);
686 if (ret != 0)
687 break;
688 ++i;
689 }
690
691 if (ret != 0) {
692 xt_entry_foreach(iter, entry0, newinfo->size) {
693 if (i-- == 0)
694 break;
695 cleanup_entry(iter);
696 }
697 return ret;
698 }
699
700 /* And one copy for every other CPU */
701 for_each_possible_cpu(i) {
702 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
703 memcpy(newinfo->entries[i], entry0, newinfo->size);
704 }
705
706 return ret;
707}
708
709static void get_counters(const struct xt_table_info *t,
710 struct xt_counters counters[])
711{
712 struct arpt_entry *iter;
713 unsigned int cpu;
714 unsigned int i;
715
716 for_each_possible_cpu(cpu) {
717 seqcount_t *s = &per_cpu(xt_recseq, cpu);
718
719 i = 0;
720 xt_entry_foreach(iter, t->entries[cpu], t->size) {
721 u64 bcnt, pcnt;
722 unsigned int start;
723
724 do {
725 start = read_seqcount_begin(s);
726 bcnt = iter->counters.bcnt;
727 pcnt = iter->counters.pcnt;
728 } while (read_seqcount_retry(s, start));
729
730 ADD_COUNTER(counters[i], bcnt, pcnt);
731 ++i;
732 }
733 }
734}
735
736static struct xt_counters *alloc_counters(const struct xt_table *table)
737{
738 unsigned int countersize;
739 struct xt_counters *counters;
740 const struct xt_table_info *private = table->private;
741
742 /* We need atomic snapshot of counters: rest doesn't change
743 * (other than comefrom, which userspace doesn't care
744 * about).
745 */
746 countersize = sizeof(struct xt_counters) * private->number;
747 counters = vzalloc(countersize);
748
749 if (counters == NULL)
750 return ERR_PTR(-ENOMEM);
751
752 get_counters(private, counters);
753
754 return counters;
755}
756
757static int copy_entries_to_user(unsigned int total_size,
758 const struct xt_table *table,
759 void __user *userptr)
760{
761 unsigned int off, num;
762 const struct arpt_entry *e;
763 struct xt_counters *counters;
764 struct xt_table_info *private = table->private;
765 int ret = 0;
766 void *loc_cpu_entry;
767
768 counters = alloc_counters(table);
769 if (IS_ERR(counters))
770 return PTR_ERR(counters);
771
772 loc_cpu_entry = private->entries[raw_smp_processor_id()];
773 /* ... then copy entire thing ... */
774 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
775 ret = -EFAULT;
776 goto free_counters;
777 }
778
779 /* FIXME: use iterator macros --RR */
780 /* ... then go back and fix counters and names */
781 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
782 const struct xt_entry_target *t;
783
784 e = (struct arpt_entry *)(loc_cpu_entry + off);
785 if (copy_to_user(userptr + off
786 + offsetof(struct arpt_entry, counters),
787 &counters[num],
788 sizeof(counters[num])) != 0) {
789 ret = -EFAULT;
790 goto free_counters;
791 }
792
793 t = arpt_get_target_c(e);
794 if (copy_to_user(userptr + off + e->target_offset
795 + offsetof(struct xt_entry_target,
796 u.user.name),
797 t->u.kernel.target->name,
798 strlen(t->u.kernel.target->name)+1) != 0) {
799 ret = -EFAULT;
800 goto free_counters;
801 }
802 }
803
804 free_counters:
805 vfree(counters);
806 return ret;
807}
808
809#ifdef CONFIG_COMPAT
810static void compat_standard_from_user(void *dst, const void *src)
811{
812 int v = *(compat_int_t *)src;
813
814 if (v > 0)
815 v += xt_compat_calc_jump(NFPROTO_ARP, v);
816 memcpy(dst, &v, sizeof(v));
817}
818
819static int compat_standard_to_user(void __user *dst, const void *src)
820{
821 compat_int_t cv = *(int *)src;
822
823 if (cv > 0)
824 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
825 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
826}
827
828static int compat_calc_entry(const struct arpt_entry *e,
829 const struct xt_table_info *info,
830 const void *base, struct xt_table_info *newinfo)
831{
832 const struct xt_entry_target *t;
833 unsigned int entry_offset;
834 int off, i, ret;
835
836 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
837 entry_offset = (void *)e - base;
838
839 t = arpt_get_target_c(e);
840 off += xt_compat_target_offset(t->u.kernel.target);
841 newinfo->size -= off;
842 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
843 if (ret)
844 return ret;
845
846 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
847 if (info->hook_entry[i] &&
848 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
849 newinfo->hook_entry[i] -= off;
850 if (info->underflow[i] &&
851 (e < (struct arpt_entry *)(base + info->underflow[i])))
852 newinfo->underflow[i] -= off;
853 }
854 return 0;
855}
856
857static int compat_table_info(const struct xt_table_info *info,
858 struct xt_table_info *newinfo)
859{
860 struct arpt_entry *iter;
861 void *loc_cpu_entry;
862 int ret;
863
864 if (!newinfo || !info)
865 return -EINVAL;
866
867 /* we dont care about newinfo->entries[] */
868 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
869 newinfo->initial_entries = 0;
870 loc_cpu_entry = info->entries[raw_smp_processor_id()];
871 xt_compat_init_offsets(NFPROTO_ARP, info->number);
872 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
873 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
874 if (ret != 0)
875 return ret;
876 }
877 return 0;
878}
879#endif
880
881static int get_info(struct net *net, void __user *user,
882 const int *len, int compat)
883{
884 char name[XT_TABLE_MAXNAMELEN];
885 struct xt_table *t;
886 int ret;
887
888 if (*len != sizeof(struct arpt_getinfo)) {
889 duprintf("length %u != %Zu\n", *len,
890 sizeof(struct arpt_getinfo));
891 return -EINVAL;
892 }
893
894 if (copy_from_user(name, user, sizeof(name)) != 0)
895 return -EFAULT;
896
897 name[XT_TABLE_MAXNAMELEN-1] = '\0';
898#ifdef CONFIG_COMPAT
899 if (compat)
900 xt_compat_lock(NFPROTO_ARP);
901#endif
902 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
903 "arptable_%s", name);
904 if (t && !IS_ERR(t)) {
905 struct arpt_getinfo info;
906 const struct xt_table_info *private = t->private;
907#ifdef CONFIG_COMPAT
908 struct xt_table_info tmp;
909
910 if (compat) {
911 ret = compat_table_info(private, &tmp);
912 xt_compat_flush_offsets(NFPROTO_ARP);
913 private = &tmp;
914 }
915#endif
916 memset(&info, 0, sizeof(info));
917 info.valid_hooks = t->valid_hooks;
918 memcpy(info.hook_entry, private->hook_entry,
919 sizeof(info.hook_entry));
920 memcpy(info.underflow, private->underflow,
921 sizeof(info.underflow));
922 info.num_entries = private->number;
923 info.size = private->size;
924 strcpy(info.name, name);
925
926 if (copy_to_user(user, &info, *len) != 0)
927 ret = -EFAULT;
928 else
929 ret = 0;
930 xt_table_unlock(t);
931 module_put(t->me);
932 } else
933 ret = t ? PTR_ERR(t) : -ENOENT;
934#ifdef CONFIG_COMPAT
935 if (compat)
936 xt_compat_unlock(NFPROTO_ARP);
937#endif
938 return ret;
939}
940
941static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
942 const int *len)
943{
944 int ret;
945 struct arpt_get_entries get;
946 struct xt_table *t;
947
948 if (*len < sizeof(get)) {
949 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
950 return -EINVAL;
951 }
952 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
953 return -EFAULT;
954 if (*len != sizeof(struct arpt_get_entries) + get.size) {
955 duprintf("get_entries: %u != %Zu\n", *len,
956 sizeof(struct arpt_get_entries) + get.size);
957 return -EINVAL;
958 }
959
960 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
961 if (t && !IS_ERR(t)) {
962 const struct xt_table_info *private = t->private;
963
964 duprintf("t->private->number = %u\n",
965 private->number);
966 if (get.size == private->size)
967 ret = copy_entries_to_user(private->size,
968 t, uptr->entrytable);
969 else {
970 duprintf("get_entries: I've got %u not %u!\n",
971 private->size, get.size);
972 ret = -EAGAIN;
973 }
974 module_put(t->me);
975 xt_table_unlock(t);
976 } else
977 ret = t ? PTR_ERR(t) : -ENOENT;
978
979 return ret;
980}
981
982static int __do_replace(struct net *net, const char *name,
983 unsigned int valid_hooks,
984 struct xt_table_info *newinfo,
985 unsigned int num_counters,
986 void __user *counters_ptr)
987{
988 int ret;
989 struct xt_table *t;
990 struct xt_table_info *oldinfo;
991 struct xt_counters *counters;
992 void *loc_cpu_old_entry;
993 struct arpt_entry *iter;
994
995 ret = 0;
996 counters = vzalloc(num_counters * sizeof(struct xt_counters));
997 if (!counters) {
998 ret = -ENOMEM;
999 goto out;
1000 }
1001
1002 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1003 "arptable_%s", name);
1004 if (!t || IS_ERR(t)) {
1005 ret = t ? PTR_ERR(t) : -ENOENT;
1006 goto free_newinfo_counters_untrans;
1007 }
1008
1009 /* You lied! */
1010 if (valid_hooks != t->valid_hooks) {
1011 duprintf("Valid hook crap: %08X vs %08X\n",
1012 valid_hooks, t->valid_hooks);
1013 ret = -EINVAL;
1014 goto put_module;
1015 }
1016
1017 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1018 if (!oldinfo)
1019 goto put_module;
1020
1021 /* Update module usage count based on number of rules */
1022 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1023 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1024 if ((oldinfo->number > oldinfo->initial_entries) ||
1025 (newinfo->number <= oldinfo->initial_entries))
1026 module_put(t->me);
1027 if ((oldinfo->number > oldinfo->initial_entries) &&
1028 (newinfo->number <= oldinfo->initial_entries))
1029 module_put(t->me);
1030
1031 /* Get the old counters, and synchronize with replace */
1032 get_counters(oldinfo, counters);
1033
1034 /* Decrease module usage counts and free resource */
1035 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1036 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1037 cleanup_entry(iter);
1038
1039 xt_free_table_info(oldinfo);
1040 if (copy_to_user(counters_ptr, counters,
1041 sizeof(struct xt_counters) * num_counters) != 0)
1042 ret = -EFAULT;
1043 vfree(counters);
1044 xt_table_unlock(t);
1045 return ret;
1046
1047 put_module:
1048 module_put(t->me);
1049 xt_table_unlock(t);
1050 free_newinfo_counters_untrans:
1051 vfree(counters);
1052 out:
1053 return ret;
1054}
1055
1056static int do_replace(struct net *net, const void __user *user,
1057 unsigned int len)
1058{
1059 int ret;
1060 struct arpt_replace tmp;
1061 struct xt_table_info *newinfo;
1062 void *loc_cpu_entry;
1063 struct arpt_entry *iter;
1064
1065 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1066 return -EFAULT;
1067
1068 /* overflow check */
1069 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1070 return -ENOMEM;
1071 tmp.name[sizeof(tmp.name)-1] = 0;
1072
1073 newinfo = xt_alloc_table_info(tmp.size);
1074 if (!newinfo)
1075 return -ENOMEM;
1076
1077 /* choose the copy that is on our node/cpu */
1078 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1079 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1080 tmp.size) != 0) {
1081 ret = -EFAULT;
1082 goto free_newinfo;
1083 }
1084
1085 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1086 if (ret != 0)
1087 goto free_newinfo;
1088
1089 duprintf("arp_tables: Translated table\n");
1090
1091 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1092 tmp.num_counters, tmp.counters);
1093 if (ret)
1094 goto free_newinfo_untrans;
1095 return 0;
1096
1097 free_newinfo_untrans:
1098 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1099 cleanup_entry(iter);
1100 free_newinfo:
1101 xt_free_table_info(newinfo);
1102 return ret;
1103}
1104
1105static int do_add_counters(struct net *net, const void __user *user,
1106 unsigned int len, int compat)
1107{
1108 unsigned int i, curcpu;
1109 struct xt_counters_info tmp;
1110 struct xt_counters *paddc;
1111 unsigned int num_counters;
1112 const char *name;
1113 int size;
1114 void *ptmp;
1115 struct xt_table *t;
1116 const struct xt_table_info *private;
1117 int ret = 0;
1118 void *loc_cpu_entry;
1119 struct arpt_entry *iter;
1120 unsigned int addend;
1121#ifdef CONFIG_COMPAT
1122 struct compat_xt_counters_info compat_tmp;
1123
1124 if (compat) {
1125 ptmp = &compat_tmp;
1126 size = sizeof(struct compat_xt_counters_info);
1127 } else
1128#endif
1129 {
1130 ptmp = &tmp;
1131 size = sizeof(struct xt_counters_info);
1132 }
1133
1134 if (copy_from_user(ptmp, user, size) != 0)
1135 return -EFAULT;
1136
1137#ifdef CONFIG_COMPAT
1138 if (compat) {
1139 num_counters = compat_tmp.num_counters;
1140 name = compat_tmp.name;
1141 } else
1142#endif
1143 {
1144 num_counters = tmp.num_counters;
1145 name = tmp.name;
1146 }
1147
1148 if (len != size + num_counters * sizeof(struct xt_counters))
1149 return -EINVAL;
1150
1151 paddc = vmalloc(len - size);
1152 if (!paddc)
1153 return -ENOMEM;
1154
1155 if (copy_from_user(paddc, user + size, len - size) != 0) {
1156 ret = -EFAULT;
1157 goto free;
1158 }
1159
1160 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1161 if (!t || IS_ERR(t)) {
1162 ret = t ? PTR_ERR(t) : -ENOENT;
1163 goto free;
1164 }
1165
1166 local_bh_disable();
1167 private = t->private;
1168 if (private->number != num_counters) {
1169 ret = -EINVAL;
1170 goto unlock_up_free;
1171 }
1172
1173 i = 0;
1174 /* Choose the copy that is on our node */
1175 curcpu = smp_processor_id();
1176 loc_cpu_entry = private->entries[curcpu];
1177 addend = xt_write_recseq_begin();
1178 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1179 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1180 ++i;
1181 }
1182 xt_write_recseq_end(addend);
1183 unlock_up_free:
1184 local_bh_enable();
1185 xt_table_unlock(t);
1186 module_put(t->me);
1187 free:
1188 vfree(paddc);
1189
1190 return ret;
1191}
1192
1193#ifdef CONFIG_COMPAT
1194static inline void compat_release_entry(struct compat_arpt_entry *e)
1195{
1196 struct xt_entry_target *t;
1197
1198 t = compat_arpt_get_target(e);
1199 module_put(t->u.kernel.target->me);
1200}
1201
1202static inline int
1203check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1204 struct xt_table_info *newinfo,
1205 unsigned int *size,
1206 const unsigned char *base,
1207 const unsigned char *limit,
1208 const unsigned int *hook_entries,
1209 const unsigned int *underflows,
1210 const char *name)
1211{
1212 struct xt_entry_target *t;
1213 struct xt_target *target;
1214 unsigned int entry_offset;
1215 int ret, off, h;
1216
1217 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1218 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1219 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1220 duprintf("Bad offset %p, limit = %p\n", e, limit);
1221 return -EINVAL;
1222 }
1223
1224 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1225 sizeof(struct compat_xt_entry_target)) {
1226 duprintf("checking: element %p size %u\n",
1227 e, e->next_offset);
1228 return -EINVAL;
1229 }
1230
1231 /* For purposes of check_entry casting the compat entry is fine */
1232 ret = check_entry((struct arpt_entry *)e, name);
1233 if (ret)
1234 return ret;
1235
1236 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1237 entry_offset = (void *)e - (void *)base;
1238
1239 t = compat_arpt_get_target(e);
1240 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1241 t->u.user.revision);
1242 if (IS_ERR(target)) {
1243 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1244 t->u.user.name);
1245 ret = PTR_ERR(target);
1246 goto out;
1247 }
1248 t->u.kernel.target = target;
1249
1250 off += xt_compat_target_offset(target);
1251 *size += off;
1252 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1253 if (ret)
1254 goto release_target;
1255
1256 /* Check hooks & underflows */
1257 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1258 if ((unsigned char *)e - base == hook_entries[h])
1259 newinfo->hook_entry[h] = hook_entries[h];
1260 if ((unsigned char *)e - base == underflows[h])
1261 newinfo->underflow[h] = underflows[h];
1262 }
1263
1264 /* Clear counters and comefrom */
1265 memset(&e->counters, 0, sizeof(e->counters));
1266 e->comefrom = 0;
1267 return 0;
1268
1269release_target:
1270 module_put(t->u.kernel.target->me);
1271out:
1272 return ret;
1273}
1274
1275static int
1276compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1277 unsigned int *size, const char *name,
1278 struct xt_table_info *newinfo, unsigned char *base)
1279{
1280 struct xt_entry_target *t;
1281 struct xt_target *target;
1282 struct arpt_entry *de;
1283 unsigned int origsize;
1284 int ret, h;
1285
1286 ret = 0;
1287 origsize = *size;
1288 de = (struct arpt_entry *)*dstptr;
1289 memcpy(de, e, sizeof(struct arpt_entry));
1290 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1291
1292 *dstptr += sizeof(struct arpt_entry);
1293 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1294
1295 de->target_offset = e->target_offset - (origsize - *size);
1296 t = compat_arpt_get_target(e);
1297 target = t->u.kernel.target;
1298 xt_compat_target_from_user(t, dstptr, size);
1299
1300 de->next_offset = e->next_offset - (origsize - *size);
1301 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1302 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1303 newinfo->hook_entry[h] -= origsize - *size;
1304 if ((unsigned char *)de - base < newinfo->underflow[h])
1305 newinfo->underflow[h] -= origsize - *size;
1306 }
1307 return ret;
1308}
1309
1310static int translate_compat_table(const char *name,
1311 unsigned int valid_hooks,
1312 struct xt_table_info **pinfo,
1313 void **pentry0,
1314 unsigned int total_size,
1315 unsigned int number,
1316 unsigned int *hook_entries,
1317 unsigned int *underflows)
1318{
1319 unsigned int i, j;
1320 struct xt_table_info *newinfo, *info;
1321 void *pos, *entry0, *entry1;
1322 struct compat_arpt_entry *iter0;
1323 struct arpt_entry *iter1;
1324 unsigned int size;
1325 int ret = 0;
1326
1327 info = *pinfo;
1328 entry0 = *pentry0;
1329 size = total_size;
1330 info->number = number;
1331
1332 /* Init all hooks to impossible value. */
1333 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1334 info->hook_entry[i] = 0xFFFFFFFF;
1335 info->underflow[i] = 0xFFFFFFFF;
1336 }
1337
1338 duprintf("translate_compat_table: size %u\n", info->size);
1339 j = 0;
1340 xt_compat_lock(NFPROTO_ARP);
1341 xt_compat_init_offsets(NFPROTO_ARP, number);
1342 /* Walk through entries, checking offsets. */
1343 xt_entry_foreach(iter0, entry0, total_size) {
1344 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1345 entry0,
1346 entry0 + total_size,
1347 hook_entries,
1348 underflows,
1349 name);
1350 if (ret != 0)
1351 goto out_unlock;
1352 ++j;
1353 }
1354
1355 ret = -EINVAL;
1356 if (j != number) {
1357 duprintf("translate_compat_table: %u not %u entries\n",
1358 j, number);
1359 goto out_unlock;
1360 }
1361
1362 /* Check hooks all assigned */
1363 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1364 /* Only hooks which are valid */
1365 if (!(valid_hooks & (1 << i)))
1366 continue;
1367 if (info->hook_entry[i] == 0xFFFFFFFF) {
1368 duprintf("Invalid hook entry %u %u\n",
1369 i, hook_entries[i]);
1370 goto out_unlock;
1371 }
1372 if (info->underflow[i] == 0xFFFFFFFF) {
1373 duprintf("Invalid underflow %u %u\n",
1374 i, underflows[i]);
1375 goto out_unlock;
1376 }
1377 }
1378
1379 ret = -ENOMEM;
1380 newinfo = xt_alloc_table_info(size);
1381 if (!newinfo)
1382 goto out_unlock;
1383
1384 newinfo->number = number;
1385 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1386 newinfo->hook_entry[i] = info->hook_entry[i];
1387 newinfo->underflow[i] = info->underflow[i];
1388 }
1389 entry1 = newinfo->entries[raw_smp_processor_id()];
1390 pos = entry1;
1391 size = total_size;
1392 xt_entry_foreach(iter0, entry0, total_size) {
1393 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1394 name, newinfo, entry1);
1395 if (ret != 0)
1396 break;
1397 }
1398 xt_compat_flush_offsets(NFPROTO_ARP);
1399 xt_compat_unlock(NFPROTO_ARP);
1400 if (ret)
1401 goto free_newinfo;
1402
1403 ret = -ELOOP;
1404 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1405 goto free_newinfo;
1406
1407 i = 0;
1408 xt_entry_foreach(iter1, entry1, newinfo->size) {
1409 ret = check_target(iter1, name);
1410 if (ret != 0)
1411 break;
1412 ++i;
1413 if (strcmp(arpt_get_target(iter1)->u.user.name,
1414 XT_ERROR_TARGET) == 0)
1415 ++newinfo->stacksize;
1416 }
1417 if (ret) {
1418 /*
1419 * The first i matches need cleanup_entry (calls ->destroy)
1420 * because they had called ->check already. The other j-i
1421 * entries need only release.
1422 */
1423 int skip = i;
1424 j -= i;
1425 xt_entry_foreach(iter0, entry0, newinfo->size) {
1426 if (skip-- > 0)
1427 continue;
1428 if (j-- == 0)
1429 break;
1430 compat_release_entry(iter0);
1431 }
1432 xt_entry_foreach(iter1, entry1, newinfo->size) {
1433 if (i-- == 0)
1434 break;
1435 cleanup_entry(iter1);
1436 }
1437 xt_free_table_info(newinfo);
1438 return ret;
1439 }
1440
1441 /* And one copy for every other CPU */
1442 for_each_possible_cpu(i)
1443 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1444 memcpy(newinfo->entries[i], entry1, newinfo->size);
1445
1446 *pinfo = newinfo;
1447 *pentry0 = entry1;
1448 xt_free_table_info(info);
1449 return 0;
1450
1451free_newinfo:
1452 xt_free_table_info(newinfo);
1453out:
1454 xt_entry_foreach(iter0, entry0, total_size) {
1455 if (j-- == 0)
1456 break;
1457 compat_release_entry(iter0);
1458 }
1459 return ret;
1460out_unlock:
1461 xt_compat_flush_offsets(NFPROTO_ARP);
1462 xt_compat_unlock(NFPROTO_ARP);
1463 goto out;
1464}
1465
1466struct compat_arpt_replace {
1467 char name[XT_TABLE_MAXNAMELEN];
1468 u32 valid_hooks;
1469 u32 num_entries;
1470 u32 size;
1471 u32 hook_entry[NF_ARP_NUMHOOKS];
1472 u32 underflow[NF_ARP_NUMHOOKS];
1473 u32 num_counters;
1474 compat_uptr_t counters;
1475 struct compat_arpt_entry entries[0];
1476};
1477
1478static int compat_do_replace(struct net *net, void __user *user,
1479 unsigned int len)
1480{
1481 int ret;
1482 struct compat_arpt_replace tmp;
1483 struct xt_table_info *newinfo;
1484 void *loc_cpu_entry;
1485 struct arpt_entry *iter;
1486
1487 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1488 return -EFAULT;
1489
1490 /* overflow check */
1491 if (tmp.size >= INT_MAX / num_possible_cpus())
1492 return -ENOMEM;
1493 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1494 return -ENOMEM;
1495 tmp.name[sizeof(tmp.name)-1] = 0;
1496
1497 newinfo = xt_alloc_table_info(tmp.size);
1498 if (!newinfo)
1499 return -ENOMEM;
1500
1501 /* choose the copy that is on our node/cpu */
1502 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1503 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1504 ret = -EFAULT;
1505 goto free_newinfo;
1506 }
1507
1508 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1509 &newinfo, &loc_cpu_entry, tmp.size,
1510 tmp.num_entries, tmp.hook_entry,
1511 tmp.underflow);
1512 if (ret != 0)
1513 goto free_newinfo;
1514
1515 duprintf("compat_do_replace: Translated table\n");
1516
1517 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1518 tmp.num_counters, compat_ptr(tmp.counters));
1519 if (ret)
1520 goto free_newinfo_untrans;
1521 return 0;
1522
1523 free_newinfo_untrans:
1524 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1525 cleanup_entry(iter);
1526 free_newinfo:
1527 xt_free_table_info(newinfo);
1528 return ret;
1529}
1530
1531static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1532 unsigned int len)
1533{
1534 int ret;
1535
1536 if (!capable(CAP_NET_ADMIN))
1537 return -EPERM;
1538
1539 switch (cmd) {
1540 case ARPT_SO_SET_REPLACE:
1541 ret = compat_do_replace(sock_net(sk), user, len);
1542 break;
1543
1544 case ARPT_SO_SET_ADD_COUNTERS:
1545 ret = do_add_counters(sock_net(sk), user, len, 1);
1546 break;
1547
1548 default:
1549 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1550 ret = -EINVAL;
1551 }
1552
1553 return ret;
1554}
1555
1556static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1557 compat_uint_t *size,
1558 struct xt_counters *counters,
1559 unsigned int i)
1560{
1561 struct xt_entry_target *t;
1562 struct compat_arpt_entry __user *ce;
1563 u_int16_t target_offset, next_offset;
1564 compat_uint_t origsize;
1565 int ret;
1566
1567 origsize = *size;
1568 ce = (struct compat_arpt_entry __user *)*dstptr;
1569 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1570 copy_to_user(&ce->counters, &counters[i],
1571 sizeof(counters[i])) != 0)
1572 return -EFAULT;
1573
1574 *dstptr += sizeof(struct compat_arpt_entry);
1575 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1576
1577 target_offset = e->target_offset - (origsize - *size);
1578
1579 t = arpt_get_target(e);
1580 ret = xt_compat_target_to_user(t, dstptr, size);
1581 if (ret)
1582 return ret;
1583 next_offset = e->next_offset - (origsize - *size);
1584 if (put_user(target_offset, &ce->target_offset) != 0 ||
1585 put_user(next_offset, &ce->next_offset) != 0)
1586 return -EFAULT;
1587 return 0;
1588}
1589
1590static int compat_copy_entries_to_user(unsigned int total_size,
1591 struct xt_table *table,
1592 void __user *userptr)
1593{
1594 struct xt_counters *counters;
1595 const struct xt_table_info *private = table->private;
1596 void __user *pos;
1597 unsigned int size;
1598 int ret = 0;
1599 void *loc_cpu_entry;
1600 unsigned int i = 0;
1601 struct arpt_entry *iter;
1602
1603 counters = alloc_counters(table);
1604 if (IS_ERR(counters))
1605 return PTR_ERR(counters);
1606
1607 /* choose the copy on our node/cpu */
1608 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1609 pos = userptr;
1610 size = total_size;
1611 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1612 ret = compat_copy_entry_to_user(iter, &pos,
1613 &size, counters, i++);
1614 if (ret != 0)
1615 break;
1616 }
1617 vfree(counters);
1618 return ret;
1619}
1620
1621struct compat_arpt_get_entries {
1622 char name[XT_TABLE_MAXNAMELEN];
1623 compat_uint_t size;
1624 struct compat_arpt_entry entrytable[0];
1625};
1626
1627static int compat_get_entries(struct net *net,
1628 struct compat_arpt_get_entries __user *uptr,
1629 int *len)
1630{
1631 int ret;
1632 struct compat_arpt_get_entries get;
1633 struct xt_table *t;
1634
1635 if (*len < sizeof(get)) {
1636 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1637 return -EINVAL;
1638 }
1639 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1640 return -EFAULT;
1641 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1642 duprintf("compat_get_entries: %u != %zu\n",
1643 *len, sizeof(get) + get.size);
1644 return -EINVAL;
1645 }
1646
1647 xt_compat_lock(NFPROTO_ARP);
1648 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1649 if (t && !IS_ERR(t)) {
1650 const struct xt_table_info *private = t->private;
1651 struct xt_table_info info;
1652
1653 duprintf("t->private->number = %u\n", private->number);
1654 ret = compat_table_info(private, &info);
1655 if (!ret && get.size == info.size) {
1656 ret = compat_copy_entries_to_user(private->size,
1657 t, uptr->entrytable);
1658 } else if (!ret) {
1659 duprintf("compat_get_entries: I've got %u not %u!\n",
1660 private->size, get.size);
1661 ret = -EAGAIN;
1662 }
1663 xt_compat_flush_offsets(NFPROTO_ARP);
1664 module_put(t->me);
1665 xt_table_unlock(t);
1666 } else
1667 ret = t ? PTR_ERR(t) : -ENOENT;
1668
1669 xt_compat_unlock(NFPROTO_ARP);
1670 return ret;
1671}
1672
1673static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1674
1675static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1676 int *len)
1677{
1678 int ret;
1679
1680 if (!capable(CAP_NET_ADMIN))
1681 return -EPERM;
1682
1683 switch (cmd) {
1684 case ARPT_SO_GET_INFO:
1685 ret = get_info(sock_net(sk), user, len, 1);
1686 break;
1687 case ARPT_SO_GET_ENTRIES:
1688 ret = compat_get_entries(sock_net(sk), user, len);
1689 break;
1690 default:
1691 ret = do_arpt_get_ctl(sk, cmd, user, len);
1692 }
1693 return ret;
1694}
1695#endif
1696
1697static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1698{
1699 int ret;
1700
1701 if (!capable(CAP_NET_ADMIN))
1702 return -EPERM;
1703
1704 switch (cmd) {
1705 case ARPT_SO_SET_REPLACE:
1706 ret = do_replace(sock_net(sk), user, len);
1707 break;
1708
1709 case ARPT_SO_SET_ADD_COUNTERS:
1710 ret = do_add_counters(sock_net(sk), user, len, 0);
1711 break;
1712
1713 default:
1714 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1715 ret = -EINVAL;
1716 }
1717
1718 return ret;
1719}
1720
1721static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1722{
1723 int ret;
1724
1725 if (!capable(CAP_NET_ADMIN))
1726 return -EPERM;
1727
1728 switch (cmd) {
1729 case ARPT_SO_GET_INFO:
1730 ret = get_info(sock_net(sk), user, len, 0);
1731 break;
1732
1733 case ARPT_SO_GET_ENTRIES:
1734 ret = get_entries(sock_net(sk), user, len);
1735 break;
1736
1737 case ARPT_SO_GET_REVISION_TARGET: {
1738 struct xt_get_revision rev;
1739
1740 if (*len != sizeof(rev)) {
1741 ret = -EINVAL;
1742 break;
1743 }
1744 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1745 ret = -EFAULT;
1746 break;
1747 }
1748 rev.name[sizeof(rev.name)-1] = 0;
1749
1750 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1751 rev.revision, 1, &ret),
1752 "arpt_%s", rev.name);
1753 break;
1754 }
1755
1756 default:
1757 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1758 ret = -EINVAL;
1759 }
1760
1761 return ret;
1762}
1763
1764struct xt_table *arpt_register_table(struct net *net,
1765 const struct xt_table *table,
1766 const struct arpt_replace *repl)
1767{
1768 int ret;
1769 struct xt_table_info *newinfo;
1770 struct xt_table_info bootstrap = {0};
1771 void *loc_cpu_entry;
1772 struct xt_table *new_table;
1773
1774 newinfo = xt_alloc_table_info(repl->size);
1775 if (!newinfo) {
1776 ret = -ENOMEM;
1777 goto out;
1778 }
1779
1780 /* choose the copy on our node/cpu */
1781 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1782 memcpy(loc_cpu_entry, repl->entries, repl->size);
1783
1784 ret = translate_table(newinfo, loc_cpu_entry, repl);
1785 duprintf("arpt_register_table: translate table gives %d\n", ret);
1786 if (ret != 0)
1787 goto out_free;
1788
1789 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1790 if (IS_ERR(new_table)) {
1791 ret = PTR_ERR(new_table);
1792 goto out_free;
1793 }
1794 return new_table;
1795
1796out_free:
1797 xt_free_table_info(newinfo);
1798out:
1799 return ERR_PTR(ret);
1800}
1801
1802void arpt_unregister_table(struct xt_table *table)
1803{
1804 struct xt_table_info *private;
1805 void *loc_cpu_entry;
1806 struct module *table_owner = table->me;
1807 struct arpt_entry *iter;
1808
1809 private = xt_unregister_table(table);
1810
1811 /* Decrease module usage counts and free resources */
1812 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1813 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1814 cleanup_entry(iter);
1815 if (private->number > private->initial_entries)
1816 module_put(table_owner);
1817 xt_free_table_info(private);
1818}
1819
1820/* The built-in targets: standard (NULL) and error. */
1821static struct xt_target arpt_builtin_tg[] __read_mostly = {
1822 {
1823 .name = XT_STANDARD_TARGET,
1824 .targetsize = sizeof(int),
1825 .family = NFPROTO_ARP,
1826#ifdef CONFIG_COMPAT
1827 .compatsize = sizeof(compat_int_t),
1828 .compat_from_user = compat_standard_from_user,
1829 .compat_to_user = compat_standard_to_user,
1830#endif
1831 },
1832 {
1833 .name = XT_ERROR_TARGET,
1834 .target = arpt_error,
1835 .targetsize = XT_FUNCTION_MAXNAMELEN,
1836 .family = NFPROTO_ARP,
1837 },
1838};
1839
1840static struct nf_sockopt_ops arpt_sockopts = {
1841 .pf = PF_INET,
1842 .set_optmin = ARPT_BASE_CTL,
1843 .set_optmax = ARPT_SO_SET_MAX+1,
1844 .set = do_arpt_set_ctl,
1845#ifdef CONFIG_COMPAT
1846 .compat_set = compat_do_arpt_set_ctl,
1847#endif
1848 .get_optmin = ARPT_BASE_CTL,
1849 .get_optmax = ARPT_SO_GET_MAX+1,
1850 .get = do_arpt_get_ctl,
1851#ifdef CONFIG_COMPAT
1852 .compat_get = compat_do_arpt_get_ctl,
1853#endif
1854 .owner = THIS_MODULE,
1855};
1856
1857static int __net_init arp_tables_net_init(struct net *net)
1858{
1859 return xt_proto_init(net, NFPROTO_ARP);
1860}
1861
1862static void __net_exit arp_tables_net_exit(struct net *net)
1863{
1864 xt_proto_fini(net, NFPROTO_ARP);
1865}
1866
1867static struct pernet_operations arp_tables_net_ops = {
1868 .init = arp_tables_net_init,
1869 .exit = arp_tables_net_exit,
1870};
1871
1872static int __init arp_tables_init(void)
1873{
1874 int ret;
1875
1876 ret = register_pernet_subsys(&arp_tables_net_ops);
1877 if (ret < 0)
1878 goto err1;
1879
1880 /* No one else will be downing sem now, so we won't sleep */
1881 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1882 if (ret < 0)
1883 goto err2;
1884
1885 /* Register setsockopt */
1886 ret = nf_register_sockopt(&arpt_sockopts);
1887 if (ret < 0)
1888 goto err4;
1889
1890 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1891 return 0;
1892
1893err4:
1894 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1895err2:
1896 unregister_pernet_subsys(&arp_tables_net_ops);
1897err1:
1898 return ret;
1899}
1900
1901static void __exit arp_tables_fini(void)
1902{
1903 nf_unregister_sockopt(&arpt_sockopts);
1904 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1905 unregister_pernet_subsys(&arp_tables_net_ops);
1906}
1907
1908EXPORT_SYMBOL(arpt_register_table);
1909EXPORT_SYMBOL(arpt_unregister_table);
1910EXPORT_SYMBOL(arpt_do_table);
1911
1912module_init(arp_tables_init);
1913module_exit(arp_tables_fini);