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Merge tag 'v3.15' into next
[deliverable/linux.git] / net / ipv4 / netfilter / arp_tables.c
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 * Copyright (C) 2006-2009 Patrick McHardy <kaber@trash.net>
10 *
11 */
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/capability.h>
17 #include <linux/if_arp.h>
18 #include <linux/kmod.h>
19 #include <linux/vmalloc.h>
20 #include <linux/proc_fs.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/mutex.h>
24 #include <linux/err.h>
25 #include <net/compat.h>
26 #include <net/sock.h>
27 #include <asm/uaccess.h>
28
29 #include <linux/netfilter/x_tables.h>
30 #include <linux/netfilter_arp/arp_tables.h>
31 #include "../../netfilter/xt_repldata.h"
32
33 MODULE_LICENSE("GPL");
34 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
35 MODULE_DESCRIPTION("arptables core");
36
37 /*#define DEBUG_ARP_TABLES*/
38 /*#define DEBUG_ARP_TABLES_USER*/
39
40 #ifdef DEBUG_ARP_TABLES
41 #define dprintf(format, args...) printk(format , ## args)
42 #else
43 #define dprintf(format, args...)
44 #endif
45
46 #ifdef DEBUG_ARP_TABLES_USER
47 #define duprintf(format, args...) printk(format , ## args)
48 #else
49 #define duprintf(format, args...)
50 #endif
51
52 #ifdef CONFIG_NETFILTER_DEBUG
53 #define ARP_NF_ASSERT(x) WARN_ON(!(x))
54 #else
55 #define ARP_NF_ASSERT(x)
56 #endif
57
58 void *arpt_alloc_initial_table(const struct xt_table *info)
59 {
60 return xt_alloc_initial_table(arpt, ARPT);
61 }
62 EXPORT_SYMBOL_GPL(arpt_alloc_initial_table);
63
64 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
65 const char *hdr_addr, int len)
66 {
67 int i, ret;
68
69 if (len > ARPT_DEV_ADDR_LEN_MAX)
70 len = ARPT_DEV_ADDR_LEN_MAX;
71
72 ret = 0;
73 for (i = 0; i < len; i++)
74 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
75
76 return ret != 0;
77 }
78
79 /*
80 * Unfortunately, _b and _mask are not aligned to an int (or long int)
81 * Some arches dont care, unrolling the loop is a win on them.
82 * For other arches, we only have a 16bit alignement.
83 */
84 static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
85 {
86 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
87 unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
88 #else
89 unsigned long ret = 0;
90 const u16 *a = (const u16 *)_a;
91 const u16 *b = (const u16 *)_b;
92 const u16 *mask = (const u16 *)_mask;
93 int i;
94
95 for (i = 0; i < IFNAMSIZ/sizeof(u16); i++)
96 ret |= (a[i] ^ b[i]) & mask[i];
97 #endif
98 return ret;
99 }
100
101 /* Returns whether packet matches rule or not. */
102 static inline int arp_packet_match(const struct arphdr *arphdr,
103 struct net_device *dev,
104 const char *indev,
105 const char *outdev,
106 const struct arpt_arp *arpinfo)
107 {
108 const char *arpptr = (char *)(arphdr + 1);
109 const char *src_devaddr, *tgt_devaddr;
110 __be32 src_ipaddr, tgt_ipaddr;
111 long ret;
112
113 #define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
114
115 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
116 ARPT_INV_ARPOP)) {
117 dprintf("ARP operation field mismatch.\n");
118 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
119 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
120 return 0;
121 }
122
123 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
124 ARPT_INV_ARPHRD)) {
125 dprintf("ARP hardware address format mismatch.\n");
126 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
127 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
128 return 0;
129 }
130
131 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
132 ARPT_INV_ARPPRO)) {
133 dprintf("ARP protocol address format mismatch.\n");
134 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
135 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
136 return 0;
137 }
138
139 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
140 ARPT_INV_ARPHLN)) {
141 dprintf("ARP hardware address length mismatch.\n");
142 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
143 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
144 return 0;
145 }
146
147 src_devaddr = arpptr;
148 arpptr += dev->addr_len;
149 memcpy(&src_ipaddr, arpptr, sizeof(u32));
150 arpptr += sizeof(u32);
151 tgt_devaddr = arpptr;
152 arpptr += dev->addr_len;
153 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
154
155 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
156 ARPT_INV_SRCDEVADDR) ||
157 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
158 ARPT_INV_TGTDEVADDR)) {
159 dprintf("Source or target device address mismatch.\n");
160
161 return 0;
162 }
163
164 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
165 ARPT_INV_SRCIP) ||
166 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
167 ARPT_INV_TGTIP)) {
168 dprintf("Source or target IP address mismatch.\n");
169
170 dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
171 &src_ipaddr,
172 &arpinfo->smsk.s_addr,
173 &arpinfo->src.s_addr,
174 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
175 dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n",
176 &tgt_ipaddr,
177 &arpinfo->tmsk.s_addr,
178 &arpinfo->tgt.s_addr,
179 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
180 return 0;
181 }
182
183 /* Look for ifname matches. */
184 ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
185
186 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
187 dprintf("VIA in mismatch (%s vs %s).%s\n",
188 indev, arpinfo->iniface,
189 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
190 return 0;
191 }
192
193 ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
194
195 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
196 dprintf("VIA out mismatch (%s vs %s).%s\n",
197 outdev, arpinfo->outiface,
198 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
199 return 0;
200 }
201
202 return 1;
203 #undef FWINV
204 }
205
206 static inline int arp_checkentry(const struct arpt_arp *arp)
207 {
208 if (arp->flags & ~ARPT_F_MASK) {
209 duprintf("Unknown flag bits set: %08X\n",
210 arp->flags & ~ARPT_F_MASK);
211 return 0;
212 }
213 if (arp->invflags & ~ARPT_INV_MASK) {
214 duprintf("Unknown invflag bits set: %08X\n",
215 arp->invflags & ~ARPT_INV_MASK);
216 return 0;
217 }
218
219 return 1;
220 }
221
222 static unsigned int
223 arpt_error(struct sk_buff *skb, const struct xt_action_param *par)
224 {
225 net_err_ratelimited("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 /*
275 * Ensure we load private-> members after we've fetched the base
276 * pointer.
277 */
278 smp_read_barrier_depends();
279 table_base = private->entries[smp_processor_id()];
280
281 e = get_entry(table_base, private->hook_entry[hook]);
282 back = get_entry(table_base, private->underflow[hook]);
283
284 acpar.in = in;
285 acpar.out = out;
286 acpar.hooknum = hook;
287 acpar.family = NFPROTO_ARP;
288 acpar.hotdrop = false;
289
290 arp = arp_hdr(skb);
291 do {
292 const struct xt_entry_target *t;
293
294 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
295 e = arpt_next_entry(e);
296 continue;
297 }
298
299 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
300
301 t = arpt_get_target_c(e);
302
303 /* Standard target? */
304 if (!t->u.kernel.target->target) {
305 int v;
306
307 v = ((struct xt_standard_target *)t)->verdict;
308 if (v < 0) {
309 /* Pop from stack? */
310 if (v != XT_RETURN) {
311 verdict = (unsigned int)(-v) - 1;
312 break;
313 }
314 e = back;
315 back = get_entry(table_base, back->comefrom);
316 continue;
317 }
318 if (table_base + v
319 != arpt_next_entry(e)) {
320 /* Save old back ptr in next entry */
321 struct arpt_entry *next = arpt_next_entry(e);
322 next->comefrom = (void *)back - table_base;
323
324 /* set back pointer to next entry */
325 back = next;
326 }
327
328 e = get_entry(table_base, v);
329 continue;
330 }
331
332 /* Targets which reenter must return
333 * abs. verdicts
334 */
335 acpar.target = t->u.kernel.target;
336 acpar.targinfo = t->data;
337 verdict = t->u.kernel.target->target(skb, &acpar);
338
339 /* Target might have changed stuff. */
340 arp = arp_hdr(skb);
341
342 if (verdict == XT_CONTINUE)
343 e = arpt_next_entry(e);
344 else
345 /* Verdict */
346 break;
347 } while (!acpar.hotdrop);
348 xt_write_recseq_end(addend);
349 local_bh_enable();
350
351 if (acpar.hotdrop)
352 return NF_DROP;
353 else
354 return verdict;
355 }
356
357 /* All zeroes == unconditional rule. */
358 static inline bool unconditional(const struct arpt_arp *arp)
359 {
360 static const struct arpt_arp uncond;
361
362 return memcmp(arp, &uncond, sizeof(uncond)) == 0;
363 }
364
365 /* Figures out from what hook each rule can be called: returns 0 if
366 * there are loops. Puts hook bitmask in comefrom.
367 */
368 static int mark_source_chains(const struct xt_table_info *newinfo,
369 unsigned int valid_hooks, void *entry0)
370 {
371 unsigned int hook;
372
373 /* No recursion; use packet counter to save back ptrs (reset
374 * to 0 as we leave), and comefrom to save source hook bitmask.
375 */
376 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
377 unsigned int pos = newinfo->hook_entry[hook];
378 struct arpt_entry *e
379 = (struct arpt_entry *)(entry0 + pos);
380
381 if (!(valid_hooks & (1 << hook)))
382 continue;
383
384 /* Set initial back pointer. */
385 e->counters.pcnt = pos;
386
387 for (;;) {
388 const struct xt_standard_target *t
389 = (void *)arpt_get_target_c(e);
390 int visited = e->comefrom & (1 << hook);
391
392 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
393 pr_notice("arptables: loop hook %u pos %u %08X.\n",
394 hook, pos, e->comefrom);
395 return 0;
396 }
397 e->comefrom
398 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
399
400 /* Unconditional return/END. */
401 if ((e->target_offset == sizeof(struct arpt_entry) &&
402 (strcmp(t->target.u.user.name,
403 XT_STANDARD_TARGET) == 0) &&
404 t->verdict < 0 && unconditional(&e->arp)) ||
405 visited) {
406 unsigned int oldpos, size;
407
408 if ((strcmp(t->target.u.user.name,
409 XT_STANDARD_TARGET) == 0) &&
410 t->verdict < -NF_MAX_VERDICT - 1) {
411 duprintf("mark_source_chains: bad "
412 "negative verdict (%i)\n",
413 t->verdict);
414 return 0;
415 }
416
417 /* Return: backtrack through the last
418 * big jump.
419 */
420 do {
421 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
422 oldpos = pos;
423 pos = e->counters.pcnt;
424 e->counters.pcnt = 0;
425
426 /* We're at the start. */
427 if (pos == oldpos)
428 goto next;
429
430 e = (struct arpt_entry *)
431 (entry0 + pos);
432 } while (oldpos == pos + e->next_offset);
433
434 /* Move along one */
435 size = e->next_offset;
436 e = (struct arpt_entry *)
437 (entry0 + pos + size);
438 e->counters.pcnt = pos;
439 pos += size;
440 } else {
441 int newpos = t->verdict;
442
443 if (strcmp(t->target.u.user.name,
444 XT_STANDARD_TARGET) == 0 &&
445 newpos >= 0) {
446 if (newpos > newinfo->size -
447 sizeof(struct arpt_entry)) {
448 duprintf("mark_source_chains: "
449 "bad verdict (%i)\n",
450 newpos);
451 return 0;
452 }
453
454 /* This a jump; chase it. */
455 duprintf("Jump rule %u -> %u\n",
456 pos, newpos);
457 } else {
458 /* ... this is a fallthru */
459 newpos = pos + e->next_offset;
460 }
461 e = (struct arpt_entry *)
462 (entry0 + newpos);
463 e->counters.pcnt = pos;
464 pos = newpos;
465 }
466 }
467 next:
468 duprintf("Finished chain %u\n", hook);
469 }
470 return 1;
471 }
472
473 static inline int check_entry(const struct arpt_entry *e, const char *name)
474 {
475 const struct xt_entry_target *t;
476
477 if (!arp_checkentry(&e->arp)) {
478 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
479 return -EINVAL;
480 }
481
482 if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
483 return -EINVAL;
484
485 t = arpt_get_target_c(e);
486 if (e->target_offset + t->u.target_size > e->next_offset)
487 return -EINVAL;
488
489 return 0;
490 }
491
492 static inline int check_target(struct arpt_entry *e, const char *name)
493 {
494 struct xt_entry_target *t = arpt_get_target(e);
495 int ret;
496 struct xt_tgchk_param par = {
497 .table = name,
498 .entryinfo = e,
499 .target = t->u.kernel.target,
500 .targinfo = t->data,
501 .hook_mask = e->comefrom,
502 .family = NFPROTO_ARP,
503 };
504
505 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
506 if (ret < 0) {
507 duprintf("arp_tables: check failed for `%s'.\n",
508 t->u.kernel.target->name);
509 return ret;
510 }
511 return 0;
512 }
513
514 static inline int
515 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
516 {
517 struct xt_entry_target *t;
518 struct xt_target *target;
519 int ret;
520
521 ret = check_entry(e, name);
522 if (ret)
523 return ret;
524
525 t = arpt_get_target(e);
526 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
527 t->u.user.revision);
528 if (IS_ERR(target)) {
529 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
530 ret = PTR_ERR(target);
531 goto out;
532 }
533 t->u.kernel.target = target;
534
535 ret = check_target(e, name);
536 if (ret)
537 goto err;
538 return 0;
539 err:
540 module_put(t->u.kernel.target->me);
541 out:
542 return ret;
543 }
544
545 static bool check_underflow(const struct arpt_entry *e)
546 {
547 const struct xt_entry_target *t;
548 unsigned int verdict;
549
550 if (!unconditional(&e->arp))
551 return false;
552 t = arpt_get_target_c(e);
553 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
554 return false;
555 verdict = ((struct xt_standard_target *)t)->verdict;
556 verdict = -verdict - 1;
557 return verdict == NF_DROP || verdict == NF_ACCEPT;
558 }
559
560 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
561 struct xt_table_info *newinfo,
562 const unsigned char *base,
563 const unsigned char *limit,
564 const unsigned int *hook_entries,
565 const unsigned int *underflows,
566 unsigned int valid_hooks)
567 {
568 unsigned int h;
569
570 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
571 (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
572 duprintf("Bad offset %p\n", e);
573 return -EINVAL;
574 }
575
576 if (e->next_offset
577 < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) {
578 duprintf("checking: element %p size %u\n",
579 e, e->next_offset);
580 return -EINVAL;
581 }
582
583 /* Check hooks & underflows */
584 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
585 if (!(valid_hooks & (1 << h)))
586 continue;
587 if ((unsigned char *)e - base == hook_entries[h])
588 newinfo->hook_entry[h] = hook_entries[h];
589 if ((unsigned char *)e - base == underflows[h]) {
590 if (!check_underflow(e)) {
591 pr_err("Underflows must be unconditional and "
592 "use the STANDARD target with "
593 "ACCEPT/DROP\n");
594 return -EINVAL;
595 }
596 newinfo->underflow[h] = underflows[h];
597 }
598 }
599
600 /* Clear counters and comefrom */
601 e->counters = ((struct xt_counters) { 0, 0 });
602 e->comefrom = 0;
603 return 0;
604 }
605
606 static inline void cleanup_entry(struct arpt_entry *e)
607 {
608 struct xt_tgdtor_param par;
609 struct xt_entry_target *t;
610
611 t = arpt_get_target(e);
612 par.target = t->u.kernel.target;
613 par.targinfo = t->data;
614 par.family = NFPROTO_ARP;
615 if (par.target->destroy != NULL)
616 par.target->destroy(&par);
617 module_put(par.target->me);
618 }
619
620 /* Checks and translates the user-supplied table segment (held in
621 * newinfo).
622 */
623 static int translate_table(struct xt_table_info *newinfo, void *entry0,
624 const struct arpt_replace *repl)
625 {
626 struct arpt_entry *iter;
627 unsigned int i;
628 int ret = 0;
629
630 newinfo->size = repl->size;
631 newinfo->number = repl->num_entries;
632
633 /* Init all hooks to impossible value. */
634 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
635 newinfo->hook_entry[i] = 0xFFFFFFFF;
636 newinfo->underflow[i] = 0xFFFFFFFF;
637 }
638
639 duprintf("translate_table: size %u\n", newinfo->size);
640 i = 0;
641
642 /* Walk through entries, checking offsets. */
643 xt_entry_foreach(iter, entry0, newinfo->size) {
644 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
645 entry0 + repl->size,
646 repl->hook_entry,
647 repl->underflow,
648 repl->valid_hooks);
649 if (ret != 0)
650 break;
651 ++i;
652 if (strcmp(arpt_get_target(iter)->u.user.name,
653 XT_ERROR_TARGET) == 0)
654 ++newinfo->stacksize;
655 }
656 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
657 if (ret != 0)
658 return ret;
659
660 if (i != repl->num_entries) {
661 duprintf("translate_table: %u not %u entries\n",
662 i, repl->num_entries);
663 return -EINVAL;
664 }
665
666 /* Check hooks all assigned */
667 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
668 /* Only hooks which are valid */
669 if (!(repl->valid_hooks & (1 << i)))
670 continue;
671 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
672 duprintf("Invalid hook entry %u %u\n",
673 i, repl->hook_entry[i]);
674 return -EINVAL;
675 }
676 if (newinfo->underflow[i] == 0xFFFFFFFF) {
677 duprintf("Invalid underflow %u %u\n",
678 i, repl->underflow[i]);
679 return -EINVAL;
680 }
681 }
682
683 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
684 duprintf("Looping hook\n");
685 return -ELOOP;
686 }
687
688 /* Finally, each sanity check must pass */
689 i = 0;
690 xt_entry_foreach(iter, entry0, newinfo->size) {
691 ret = find_check_entry(iter, repl->name, repl->size);
692 if (ret != 0)
693 break;
694 ++i;
695 }
696
697 if (ret != 0) {
698 xt_entry_foreach(iter, entry0, newinfo->size) {
699 if (i-- == 0)
700 break;
701 cleanup_entry(iter);
702 }
703 return ret;
704 }
705
706 /* And one copy for every other CPU */
707 for_each_possible_cpu(i) {
708 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
709 memcpy(newinfo->entries[i], entry0, newinfo->size);
710 }
711
712 return ret;
713 }
714
715 static void get_counters(const struct xt_table_info *t,
716 struct xt_counters counters[])
717 {
718 struct arpt_entry *iter;
719 unsigned int cpu;
720 unsigned int i;
721
722 for_each_possible_cpu(cpu) {
723 seqcount_t *s = &per_cpu(xt_recseq, cpu);
724
725 i = 0;
726 xt_entry_foreach(iter, t->entries[cpu], t->size) {
727 u64 bcnt, pcnt;
728 unsigned int start;
729
730 do {
731 start = read_seqcount_begin(s);
732 bcnt = iter->counters.bcnt;
733 pcnt = iter->counters.pcnt;
734 } while (read_seqcount_retry(s, start));
735
736 ADD_COUNTER(counters[i], bcnt, pcnt);
737 ++i;
738 }
739 }
740 }
741
742 static struct xt_counters *alloc_counters(const struct xt_table *table)
743 {
744 unsigned int countersize;
745 struct xt_counters *counters;
746 const struct xt_table_info *private = table->private;
747
748 /* We need atomic snapshot of counters: rest doesn't change
749 * (other than comefrom, which userspace doesn't care
750 * about).
751 */
752 countersize = sizeof(struct xt_counters) * private->number;
753 counters = vzalloc(countersize);
754
755 if (counters == NULL)
756 return ERR_PTR(-ENOMEM);
757
758 get_counters(private, counters);
759
760 return counters;
761 }
762
763 static int copy_entries_to_user(unsigned int total_size,
764 const struct xt_table *table,
765 void __user *userptr)
766 {
767 unsigned int off, num;
768 const struct arpt_entry *e;
769 struct xt_counters *counters;
770 struct xt_table_info *private = table->private;
771 int ret = 0;
772 void *loc_cpu_entry;
773
774 counters = alloc_counters(table);
775 if (IS_ERR(counters))
776 return PTR_ERR(counters);
777
778 loc_cpu_entry = private->entries[raw_smp_processor_id()];
779 /* ... then copy entire thing ... */
780 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
781 ret = -EFAULT;
782 goto free_counters;
783 }
784
785 /* FIXME: use iterator macros --RR */
786 /* ... then go back and fix counters and names */
787 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
788 const struct xt_entry_target *t;
789
790 e = (struct arpt_entry *)(loc_cpu_entry + off);
791 if (copy_to_user(userptr + off
792 + offsetof(struct arpt_entry, counters),
793 &counters[num],
794 sizeof(counters[num])) != 0) {
795 ret = -EFAULT;
796 goto free_counters;
797 }
798
799 t = arpt_get_target_c(e);
800 if (copy_to_user(userptr + off + e->target_offset
801 + offsetof(struct xt_entry_target,
802 u.user.name),
803 t->u.kernel.target->name,
804 strlen(t->u.kernel.target->name)+1) != 0) {
805 ret = -EFAULT;
806 goto free_counters;
807 }
808 }
809
810 free_counters:
811 vfree(counters);
812 return ret;
813 }
814
815 #ifdef CONFIG_COMPAT
816 static void compat_standard_from_user(void *dst, const void *src)
817 {
818 int v = *(compat_int_t *)src;
819
820 if (v > 0)
821 v += xt_compat_calc_jump(NFPROTO_ARP, v);
822 memcpy(dst, &v, sizeof(v));
823 }
824
825 static int compat_standard_to_user(void __user *dst, const void *src)
826 {
827 compat_int_t cv = *(int *)src;
828
829 if (cv > 0)
830 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
831 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
832 }
833
834 static int compat_calc_entry(const struct arpt_entry *e,
835 const struct xt_table_info *info,
836 const void *base, struct xt_table_info *newinfo)
837 {
838 const struct xt_entry_target *t;
839 unsigned int entry_offset;
840 int off, i, ret;
841
842 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
843 entry_offset = (void *)e - base;
844
845 t = arpt_get_target_c(e);
846 off += xt_compat_target_offset(t->u.kernel.target);
847 newinfo->size -= off;
848 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
849 if (ret)
850 return ret;
851
852 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
853 if (info->hook_entry[i] &&
854 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
855 newinfo->hook_entry[i] -= off;
856 if (info->underflow[i] &&
857 (e < (struct arpt_entry *)(base + info->underflow[i])))
858 newinfo->underflow[i] -= off;
859 }
860 return 0;
861 }
862
863 static int compat_table_info(const struct xt_table_info *info,
864 struct xt_table_info *newinfo)
865 {
866 struct arpt_entry *iter;
867 void *loc_cpu_entry;
868 int ret;
869
870 if (!newinfo || !info)
871 return -EINVAL;
872
873 /* we dont care about newinfo->entries[] */
874 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
875 newinfo->initial_entries = 0;
876 loc_cpu_entry = info->entries[raw_smp_processor_id()];
877 xt_compat_init_offsets(NFPROTO_ARP, info->number);
878 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
879 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
880 if (ret != 0)
881 return ret;
882 }
883 return 0;
884 }
885 #endif
886
887 static int get_info(struct net *net, void __user *user,
888 const int *len, int compat)
889 {
890 char name[XT_TABLE_MAXNAMELEN];
891 struct xt_table *t;
892 int ret;
893
894 if (*len != sizeof(struct arpt_getinfo)) {
895 duprintf("length %u != %Zu\n", *len,
896 sizeof(struct arpt_getinfo));
897 return -EINVAL;
898 }
899
900 if (copy_from_user(name, user, sizeof(name)) != 0)
901 return -EFAULT;
902
903 name[XT_TABLE_MAXNAMELEN-1] = '\0';
904 #ifdef CONFIG_COMPAT
905 if (compat)
906 xt_compat_lock(NFPROTO_ARP);
907 #endif
908 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
909 "arptable_%s", name);
910 if (!IS_ERR_OR_NULL(t)) {
911 struct arpt_getinfo info;
912 const struct xt_table_info *private = t->private;
913 #ifdef CONFIG_COMPAT
914 struct xt_table_info tmp;
915
916 if (compat) {
917 ret = compat_table_info(private, &tmp);
918 xt_compat_flush_offsets(NFPROTO_ARP);
919 private = &tmp;
920 }
921 #endif
922 memset(&info, 0, sizeof(info));
923 info.valid_hooks = t->valid_hooks;
924 memcpy(info.hook_entry, private->hook_entry,
925 sizeof(info.hook_entry));
926 memcpy(info.underflow, private->underflow,
927 sizeof(info.underflow));
928 info.num_entries = private->number;
929 info.size = private->size;
930 strcpy(info.name, name);
931
932 if (copy_to_user(user, &info, *len) != 0)
933 ret = -EFAULT;
934 else
935 ret = 0;
936 xt_table_unlock(t);
937 module_put(t->me);
938 } else
939 ret = t ? PTR_ERR(t) : -ENOENT;
940 #ifdef CONFIG_COMPAT
941 if (compat)
942 xt_compat_unlock(NFPROTO_ARP);
943 #endif
944 return ret;
945 }
946
947 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
948 const int *len)
949 {
950 int ret;
951 struct arpt_get_entries get;
952 struct xt_table *t;
953
954 if (*len < sizeof(get)) {
955 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
956 return -EINVAL;
957 }
958 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
959 return -EFAULT;
960 if (*len != sizeof(struct arpt_get_entries) + get.size) {
961 duprintf("get_entries: %u != %Zu\n", *len,
962 sizeof(struct arpt_get_entries) + get.size);
963 return -EINVAL;
964 }
965
966 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
967 if (!IS_ERR_OR_NULL(t)) {
968 const struct xt_table_info *private = t->private;
969
970 duprintf("t->private->number = %u\n",
971 private->number);
972 if (get.size == private->size)
973 ret = copy_entries_to_user(private->size,
974 t, uptr->entrytable);
975 else {
976 duprintf("get_entries: I've got %u not %u!\n",
977 private->size, get.size);
978 ret = -EAGAIN;
979 }
980 module_put(t->me);
981 xt_table_unlock(t);
982 } else
983 ret = t ? PTR_ERR(t) : -ENOENT;
984
985 return ret;
986 }
987
988 static int __do_replace(struct net *net, const char *name,
989 unsigned int valid_hooks,
990 struct xt_table_info *newinfo,
991 unsigned int num_counters,
992 void __user *counters_ptr)
993 {
994 int ret;
995 struct xt_table *t;
996 struct xt_table_info *oldinfo;
997 struct xt_counters *counters;
998 void *loc_cpu_old_entry;
999 struct arpt_entry *iter;
1000
1001 ret = 0;
1002 counters = vzalloc(num_counters * sizeof(struct xt_counters));
1003 if (!counters) {
1004 ret = -ENOMEM;
1005 goto out;
1006 }
1007
1008 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1009 "arptable_%s", name);
1010 if (IS_ERR_OR_NULL(t)) {
1011 ret = t ? PTR_ERR(t) : -ENOENT;
1012 goto free_newinfo_counters_untrans;
1013 }
1014
1015 /* You lied! */
1016 if (valid_hooks != t->valid_hooks) {
1017 duprintf("Valid hook crap: %08X vs %08X\n",
1018 valid_hooks, t->valid_hooks);
1019 ret = -EINVAL;
1020 goto put_module;
1021 }
1022
1023 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1024 if (!oldinfo)
1025 goto put_module;
1026
1027 /* Update module usage count based on number of rules */
1028 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1029 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1030 if ((oldinfo->number > oldinfo->initial_entries) ||
1031 (newinfo->number <= oldinfo->initial_entries))
1032 module_put(t->me);
1033 if ((oldinfo->number > oldinfo->initial_entries) &&
1034 (newinfo->number <= oldinfo->initial_entries))
1035 module_put(t->me);
1036
1037 /* Get the old counters, and synchronize with replace */
1038 get_counters(oldinfo, counters);
1039
1040 /* Decrease module usage counts and free resource */
1041 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1042 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1043 cleanup_entry(iter);
1044
1045 xt_free_table_info(oldinfo);
1046 if (copy_to_user(counters_ptr, counters,
1047 sizeof(struct xt_counters) * num_counters) != 0) {
1048 /* Silent error, can't fail, new table is already in place */
1049 net_warn_ratelimited("arptables: counters copy to user failed while replacing table\n");
1050 }
1051 vfree(counters);
1052 xt_table_unlock(t);
1053 return ret;
1054
1055 put_module:
1056 module_put(t->me);
1057 xt_table_unlock(t);
1058 free_newinfo_counters_untrans:
1059 vfree(counters);
1060 out:
1061 return ret;
1062 }
1063
1064 static int do_replace(struct net *net, const void __user *user,
1065 unsigned int len)
1066 {
1067 int ret;
1068 struct arpt_replace tmp;
1069 struct xt_table_info *newinfo;
1070 void *loc_cpu_entry;
1071 struct arpt_entry *iter;
1072
1073 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1074 return -EFAULT;
1075
1076 /* overflow check */
1077 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1078 return -ENOMEM;
1079 tmp.name[sizeof(tmp.name)-1] = 0;
1080
1081 newinfo = xt_alloc_table_info(tmp.size);
1082 if (!newinfo)
1083 return -ENOMEM;
1084
1085 /* choose the copy that is on our node/cpu */
1086 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1087 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1088 tmp.size) != 0) {
1089 ret = -EFAULT;
1090 goto free_newinfo;
1091 }
1092
1093 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1094 if (ret != 0)
1095 goto free_newinfo;
1096
1097 duprintf("arp_tables: Translated table\n");
1098
1099 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1100 tmp.num_counters, tmp.counters);
1101 if (ret)
1102 goto free_newinfo_untrans;
1103 return 0;
1104
1105 free_newinfo_untrans:
1106 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1107 cleanup_entry(iter);
1108 free_newinfo:
1109 xt_free_table_info(newinfo);
1110 return ret;
1111 }
1112
1113 static int do_add_counters(struct net *net, const void __user *user,
1114 unsigned int len, int compat)
1115 {
1116 unsigned int i, curcpu;
1117 struct xt_counters_info tmp;
1118 struct xt_counters *paddc;
1119 unsigned int num_counters;
1120 const char *name;
1121 int size;
1122 void *ptmp;
1123 struct xt_table *t;
1124 const struct xt_table_info *private;
1125 int ret = 0;
1126 void *loc_cpu_entry;
1127 struct arpt_entry *iter;
1128 unsigned int addend;
1129 #ifdef CONFIG_COMPAT
1130 struct compat_xt_counters_info compat_tmp;
1131
1132 if (compat) {
1133 ptmp = &compat_tmp;
1134 size = sizeof(struct compat_xt_counters_info);
1135 } else
1136 #endif
1137 {
1138 ptmp = &tmp;
1139 size = sizeof(struct xt_counters_info);
1140 }
1141
1142 if (copy_from_user(ptmp, user, size) != 0)
1143 return -EFAULT;
1144
1145 #ifdef CONFIG_COMPAT
1146 if (compat) {
1147 num_counters = compat_tmp.num_counters;
1148 name = compat_tmp.name;
1149 } else
1150 #endif
1151 {
1152 num_counters = tmp.num_counters;
1153 name = tmp.name;
1154 }
1155
1156 if (len != size + num_counters * sizeof(struct xt_counters))
1157 return -EINVAL;
1158
1159 paddc = vmalloc(len - size);
1160 if (!paddc)
1161 return -ENOMEM;
1162
1163 if (copy_from_user(paddc, user + size, len - size) != 0) {
1164 ret = -EFAULT;
1165 goto free;
1166 }
1167
1168 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1169 if (IS_ERR_OR_NULL(t)) {
1170 ret = t ? PTR_ERR(t) : -ENOENT;
1171 goto free;
1172 }
1173
1174 local_bh_disable();
1175 private = t->private;
1176 if (private->number != num_counters) {
1177 ret = -EINVAL;
1178 goto unlock_up_free;
1179 }
1180
1181 i = 0;
1182 /* Choose the copy that is on our node */
1183 curcpu = smp_processor_id();
1184 loc_cpu_entry = private->entries[curcpu];
1185 addend = xt_write_recseq_begin();
1186 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1187 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1188 ++i;
1189 }
1190 xt_write_recseq_end(addend);
1191 unlock_up_free:
1192 local_bh_enable();
1193 xt_table_unlock(t);
1194 module_put(t->me);
1195 free:
1196 vfree(paddc);
1197
1198 return ret;
1199 }
1200
1201 #ifdef CONFIG_COMPAT
1202 static inline void compat_release_entry(struct compat_arpt_entry *e)
1203 {
1204 struct xt_entry_target *t;
1205
1206 t = compat_arpt_get_target(e);
1207 module_put(t->u.kernel.target->me);
1208 }
1209
1210 static inline int
1211 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1212 struct xt_table_info *newinfo,
1213 unsigned int *size,
1214 const unsigned char *base,
1215 const unsigned char *limit,
1216 const unsigned int *hook_entries,
1217 const unsigned int *underflows,
1218 const char *name)
1219 {
1220 struct xt_entry_target *t;
1221 struct xt_target *target;
1222 unsigned int entry_offset;
1223 int ret, off, h;
1224
1225 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1226 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1227 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1228 duprintf("Bad offset %p, limit = %p\n", e, limit);
1229 return -EINVAL;
1230 }
1231
1232 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1233 sizeof(struct compat_xt_entry_target)) {
1234 duprintf("checking: element %p size %u\n",
1235 e, e->next_offset);
1236 return -EINVAL;
1237 }
1238
1239 /* For purposes of check_entry casting the compat entry is fine */
1240 ret = check_entry((struct arpt_entry *)e, name);
1241 if (ret)
1242 return ret;
1243
1244 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1245 entry_offset = (void *)e - (void *)base;
1246
1247 t = compat_arpt_get_target(e);
1248 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1249 t->u.user.revision);
1250 if (IS_ERR(target)) {
1251 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1252 t->u.user.name);
1253 ret = PTR_ERR(target);
1254 goto out;
1255 }
1256 t->u.kernel.target = target;
1257
1258 off += xt_compat_target_offset(target);
1259 *size += off;
1260 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1261 if (ret)
1262 goto release_target;
1263
1264 /* Check hooks & underflows */
1265 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1266 if ((unsigned char *)e - base == hook_entries[h])
1267 newinfo->hook_entry[h] = hook_entries[h];
1268 if ((unsigned char *)e - base == underflows[h])
1269 newinfo->underflow[h] = underflows[h];
1270 }
1271
1272 /* Clear counters and comefrom */
1273 memset(&e->counters, 0, sizeof(e->counters));
1274 e->comefrom = 0;
1275 return 0;
1276
1277 release_target:
1278 module_put(t->u.kernel.target->me);
1279 out:
1280 return ret;
1281 }
1282
1283 static int
1284 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1285 unsigned int *size, const char *name,
1286 struct xt_table_info *newinfo, unsigned char *base)
1287 {
1288 struct xt_entry_target *t;
1289 struct xt_target *target;
1290 struct arpt_entry *de;
1291 unsigned int origsize;
1292 int ret, h;
1293
1294 ret = 0;
1295 origsize = *size;
1296 de = (struct arpt_entry *)*dstptr;
1297 memcpy(de, e, sizeof(struct arpt_entry));
1298 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1299
1300 *dstptr += sizeof(struct arpt_entry);
1301 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1302
1303 de->target_offset = e->target_offset - (origsize - *size);
1304 t = compat_arpt_get_target(e);
1305 target = t->u.kernel.target;
1306 xt_compat_target_from_user(t, dstptr, size);
1307
1308 de->next_offset = e->next_offset - (origsize - *size);
1309 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1310 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1311 newinfo->hook_entry[h] -= origsize - *size;
1312 if ((unsigned char *)de - base < newinfo->underflow[h])
1313 newinfo->underflow[h] -= origsize - *size;
1314 }
1315 return ret;
1316 }
1317
1318 static int translate_compat_table(const char *name,
1319 unsigned int valid_hooks,
1320 struct xt_table_info **pinfo,
1321 void **pentry0,
1322 unsigned int total_size,
1323 unsigned int number,
1324 unsigned int *hook_entries,
1325 unsigned int *underflows)
1326 {
1327 unsigned int i, j;
1328 struct xt_table_info *newinfo, *info;
1329 void *pos, *entry0, *entry1;
1330 struct compat_arpt_entry *iter0;
1331 struct arpt_entry *iter1;
1332 unsigned int size;
1333 int ret = 0;
1334
1335 info = *pinfo;
1336 entry0 = *pentry0;
1337 size = total_size;
1338 info->number = number;
1339
1340 /* Init all hooks to impossible value. */
1341 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1342 info->hook_entry[i] = 0xFFFFFFFF;
1343 info->underflow[i] = 0xFFFFFFFF;
1344 }
1345
1346 duprintf("translate_compat_table: size %u\n", info->size);
1347 j = 0;
1348 xt_compat_lock(NFPROTO_ARP);
1349 xt_compat_init_offsets(NFPROTO_ARP, number);
1350 /* Walk through entries, checking offsets. */
1351 xt_entry_foreach(iter0, entry0, total_size) {
1352 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1353 entry0,
1354 entry0 + total_size,
1355 hook_entries,
1356 underflows,
1357 name);
1358 if (ret != 0)
1359 goto out_unlock;
1360 ++j;
1361 }
1362
1363 ret = -EINVAL;
1364 if (j != number) {
1365 duprintf("translate_compat_table: %u not %u entries\n",
1366 j, number);
1367 goto out_unlock;
1368 }
1369
1370 /* Check hooks all assigned */
1371 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1372 /* Only hooks which are valid */
1373 if (!(valid_hooks & (1 << i)))
1374 continue;
1375 if (info->hook_entry[i] == 0xFFFFFFFF) {
1376 duprintf("Invalid hook entry %u %u\n",
1377 i, hook_entries[i]);
1378 goto out_unlock;
1379 }
1380 if (info->underflow[i] == 0xFFFFFFFF) {
1381 duprintf("Invalid underflow %u %u\n",
1382 i, underflows[i]);
1383 goto out_unlock;
1384 }
1385 }
1386
1387 ret = -ENOMEM;
1388 newinfo = xt_alloc_table_info(size);
1389 if (!newinfo)
1390 goto out_unlock;
1391
1392 newinfo->number = number;
1393 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1394 newinfo->hook_entry[i] = info->hook_entry[i];
1395 newinfo->underflow[i] = info->underflow[i];
1396 }
1397 entry1 = newinfo->entries[raw_smp_processor_id()];
1398 pos = entry1;
1399 size = total_size;
1400 xt_entry_foreach(iter0, entry0, total_size) {
1401 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1402 name, newinfo, entry1);
1403 if (ret != 0)
1404 break;
1405 }
1406 xt_compat_flush_offsets(NFPROTO_ARP);
1407 xt_compat_unlock(NFPROTO_ARP);
1408 if (ret)
1409 goto free_newinfo;
1410
1411 ret = -ELOOP;
1412 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1413 goto free_newinfo;
1414
1415 i = 0;
1416 xt_entry_foreach(iter1, entry1, newinfo->size) {
1417 ret = check_target(iter1, name);
1418 if (ret != 0)
1419 break;
1420 ++i;
1421 if (strcmp(arpt_get_target(iter1)->u.user.name,
1422 XT_ERROR_TARGET) == 0)
1423 ++newinfo->stacksize;
1424 }
1425 if (ret) {
1426 /*
1427 * The first i matches need cleanup_entry (calls ->destroy)
1428 * because they had called ->check already. The other j-i
1429 * entries need only release.
1430 */
1431 int skip = i;
1432 j -= i;
1433 xt_entry_foreach(iter0, entry0, newinfo->size) {
1434 if (skip-- > 0)
1435 continue;
1436 if (j-- == 0)
1437 break;
1438 compat_release_entry(iter0);
1439 }
1440 xt_entry_foreach(iter1, entry1, newinfo->size) {
1441 if (i-- == 0)
1442 break;
1443 cleanup_entry(iter1);
1444 }
1445 xt_free_table_info(newinfo);
1446 return ret;
1447 }
1448
1449 /* And one copy for every other CPU */
1450 for_each_possible_cpu(i)
1451 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1452 memcpy(newinfo->entries[i], entry1, newinfo->size);
1453
1454 *pinfo = newinfo;
1455 *pentry0 = entry1;
1456 xt_free_table_info(info);
1457 return 0;
1458
1459 free_newinfo:
1460 xt_free_table_info(newinfo);
1461 out:
1462 xt_entry_foreach(iter0, entry0, total_size) {
1463 if (j-- == 0)
1464 break;
1465 compat_release_entry(iter0);
1466 }
1467 return ret;
1468 out_unlock:
1469 xt_compat_flush_offsets(NFPROTO_ARP);
1470 xt_compat_unlock(NFPROTO_ARP);
1471 goto out;
1472 }
1473
1474 struct compat_arpt_replace {
1475 char name[XT_TABLE_MAXNAMELEN];
1476 u32 valid_hooks;
1477 u32 num_entries;
1478 u32 size;
1479 u32 hook_entry[NF_ARP_NUMHOOKS];
1480 u32 underflow[NF_ARP_NUMHOOKS];
1481 u32 num_counters;
1482 compat_uptr_t counters;
1483 struct compat_arpt_entry entries[0];
1484 };
1485
1486 static int compat_do_replace(struct net *net, void __user *user,
1487 unsigned int len)
1488 {
1489 int ret;
1490 struct compat_arpt_replace tmp;
1491 struct xt_table_info *newinfo;
1492 void *loc_cpu_entry;
1493 struct arpt_entry *iter;
1494
1495 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1496 return -EFAULT;
1497
1498 /* overflow check */
1499 if (tmp.size >= INT_MAX / num_possible_cpus())
1500 return -ENOMEM;
1501 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1502 return -ENOMEM;
1503 tmp.name[sizeof(tmp.name)-1] = 0;
1504
1505 newinfo = xt_alloc_table_info(tmp.size);
1506 if (!newinfo)
1507 return -ENOMEM;
1508
1509 /* choose the copy that is on our node/cpu */
1510 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1511 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1512 ret = -EFAULT;
1513 goto free_newinfo;
1514 }
1515
1516 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1517 &newinfo, &loc_cpu_entry, tmp.size,
1518 tmp.num_entries, tmp.hook_entry,
1519 tmp.underflow);
1520 if (ret != 0)
1521 goto free_newinfo;
1522
1523 duprintf("compat_do_replace: Translated table\n");
1524
1525 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1526 tmp.num_counters, compat_ptr(tmp.counters));
1527 if (ret)
1528 goto free_newinfo_untrans;
1529 return 0;
1530
1531 free_newinfo_untrans:
1532 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1533 cleanup_entry(iter);
1534 free_newinfo:
1535 xt_free_table_info(newinfo);
1536 return ret;
1537 }
1538
1539 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1540 unsigned int len)
1541 {
1542 int ret;
1543
1544 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1545 return -EPERM;
1546
1547 switch (cmd) {
1548 case ARPT_SO_SET_REPLACE:
1549 ret = compat_do_replace(sock_net(sk), user, len);
1550 break;
1551
1552 case ARPT_SO_SET_ADD_COUNTERS:
1553 ret = do_add_counters(sock_net(sk), user, len, 1);
1554 break;
1555
1556 default:
1557 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1558 ret = -EINVAL;
1559 }
1560
1561 return ret;
1562 }
1563
1564 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1565 compat_uint_t *size,
1566 struct xt_counters *counters,
1567 unsigned int i)
1568 {
1569 struct xt_entry_target *t;
1570 struct compat_arpt_entry __user *ce;
1571 u_int16_t target_offset, next_offset;
1572 compat_uint_t origsize;
1573 int ret;
1574
1575 origsize = *size;
1576 ce = (struct compat_arpt_entry __user *)*dstptr;
1577 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1578 copy_to_user(&ce->counters, &counters[i],
1579 sizeof(counters[i])) != 0)
1580 return -EFAULT;
1581
1582 *dstptr += sizeof(struct compat_arpt_entry);
1583 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1584
1585 target_offset = e->target_offset - (origsize - *size);
1586
1587 t = arpt_get_target(e);
1588 ret = xt_compat_target_to_user(t, dstptr, size);
1589 if (ret)
1590 return ret;
1591 next_offset = e->next_offset - (origsize - *size);
1592 if (put_user(target_offset, &ce->target_offset) != 0 ||
1593 put_user(next_offset, &ce->next_offset) != 0)
1594 return -EFAULT;
1595 return 0;
1596 }
1597
1598 static int compat_copy_entries_to_user(unsigned int total_size,
1599 struct xt_table *table,
1600 void __user *userptr)
1601 {
1602 struct xt_counters *counters;
1603 const struct xt_table_info *private = table->private;
1604 void __user *pos;
1605 unsigned int size;
1606 int ret = 0;
1607 void *loc_cpu_entry;
1608 unsigned int i = 0;
1609 struct arpt_entry *iter;
1610
1611 counters = alloc_counters(table);
1612 if (IS_ERR(counters))
1613 return PTR_ERR(counters);
1614
1615 /* choose the copy on our node/cpu */
1616 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1617 pos = userptr;
1618 size = total_size;
1619 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1620 ret = compat_copy_entry_to_user(iter, &pos,
1621 &size, counters, i++);
1622 if (ret != 0)
1623 break;
1624 }
1625 vfree(counters);
1626 return ret;
1627 }
1628
1629 struct compat_arpt_get_entries {
1630 char name[XT_TABLE_MAXNAMELEN];
1631 compat_uint_t size;
1632 struct compat_arpt_entry entrytable[0];
1633 };
1634
1635 static int compat_get_entries(struct net *net,
1636 struct compat_arpt_get_entries __user *uptr,
1637 int *len)
1638 {
1639 int ret;
1640 struct compat_arpt_get_entries get;
1641 struct xt_table *t;
1642
1643 if (*len < sizeof(get)) {
1644 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1645 return -EINVAL;
1646 }
1647 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1648 return -EFAULT;
1649 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1650 duprintf("compat_get_entries: %u != %zu\n",
1651 *len, sizeof(get) + get.size);
1652 return -EINVAL;
1653 }
1654
1655 xt_compat_lock(NFPROTO_ARP);
1656 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1657 if (!IS_ERR_OR_NULL(t)) {
1658 const struct xt_table_info *private = t->private;
1659 struct xt_table_info info;
1660
1661 duprintf("t->private->number = %u\n", private->number);
1662 ret = compat_table_info(private, &info);
1663 if (!ret && get.size == info.size) {
1664 ret = compat_copy_entries_to_user(private->size,
1665 t, uptr->entrytable);
1666 } else if (!ret) {
1667 duprintf("compat_get_entries: I've got %u not %u!\n",
1668 private->size, get.size);
1669 ret = -EAGAIN;
1670 }
1671 xt_compat_flush_offsets(NFPROTO_ARP);
1672 module_put(t->me);
1673 xt_table_unlock(t);
1674 } else
1675 ret = t ? PTR_ERR(t) : -ENOENT;
1676
1677 xt_compat_unlock(NFPROTO_ARP);
1678 return ret;
1679 }
1680
1681 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1682
1683 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1684 int *len)
1685 {
1686 int ret;
1687
1688 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1689 return -EPERM;
1690
1691 switch (cmd) {
1692 case ARPT_SO_GET_INFO:
1693 ret = get_info(sock_net(sk), user, len, 1);
1694 break;
1695 case ARPT_SO_GET_ENTRIES:
1696 ret = compat_get_entries(sock_net(sk), user, len);
1697 break;
1698 default:
1699 ret = do_arpt_get_ctl(sk, cmd, user, len);
1700 }
1701 return ret;
1702 }
1703 #endif
1704
1705 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1706 {
1707 int ret;
1708
1709 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1710 return -EPERM;
1711
1712 switch (cmd) {
1713 case ARPT_SO_SET_REPLACE:
1714 ret = do_replace(sock_net(sk), user, len);
1715 break;
1716
1717 case ARPT_SO_SET_ADD_COUNTERS:
1718 ret = do_add_counters(sock_net(sk), user, len, 0);
1719 break;
1720
1721 default:
1722 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1723 ret = -EINVAL;
1724 }
1725
1726 return ret;
1727 }
1728
1729 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1730 {
1731 int ret;
1732
1733 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1734 return -EPERM;
1735
1736 switch (cmd) {
1737 case ARPT_SO_GET_INFO:
1738 ret = get_info(sock_net(sk), user, len, 0);
1739 break;
1740
1741 case ARPT_SO_GET_ENTRIES:
1742 ret = get_entries(sock_net(sk), user, len);
1743 break;
1744
1745 case ARPT_SO_GET_REVISION_TARGET: {
1746 struct xt_get_revision rev;
1747
1748 if (*len != sizeof(rev)) {
1749 ret = -EINVAL;
1750 break;
1751 }
1752 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1753 ret = -EFAULT;
1754 break;
1755 }
1756 rev.name[sizeof(rev.name)-1] = 0;
1757
1758 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1759 rev.revision, 1, &ret),
1760 "arpt_%s", rev.name);
1761 break;
1762 }
1763
1764 default:
1765 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1766 ret = -EINVAL;
1767 }
1768
1769 return ret;
1770 }
1771
1772 struct xt_table *arpt_register_table(struct net *net,
1773 const struct xt_table *table,
1774 const struct arpt_replace *repl)
1775 {
1776 int ret;
1777 struct xt_table_info *newinfo;
1778 struct xt_table_info bootstrap = {0};
1779 void *loc_cpu_entry;
1780 struct xt_table *new_table;
1781
1782 newinfo = xt_alloc_table_info(repl->size);
1783 if (!newinfo) {
1784 ret = -ENOMEM;
1785 goto out;
1786 }
1787
1788 /* choose the copy on our node/cpu */
1789 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1790 memcpy(loc_cpu_entry, repl->entries, repl->size);
1791
1792 ret = translate_table(newinfo, loc_cpu_entry, repl);
1793 duprintf("arpt_register_table: translate table gives %d\n", ret);
1794 if (ret != 0)
1795 goto out_free;
1796
1797 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1798 if (IS_ERR(new_table)) {
1799 ret = PTR_ERR(new_table);
1800 goto out_free;
1801 }
1802 return new_table;
1803
1804 out_free:
1805 xt_free_table_info(newinfo);
1806 out:
1807 return ERR_PTR(ret);
1808 }
1809
1810 void arpt_unregister_table(struct xt_table *table)
1811 {
1812 struct xt_table_info *private;
1813 void *loc_cpu_entry;
1814 struct module *table_owner = table->me;
1815 struct arpt_entry *iter;
1816
1817 private = xt_unregister_table(table);
1818
1819 /* Decrease module usage counts and free resources */
1820 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1821 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1822 cleanup_entry(iter);
1823 if (private->number > private->initial_entries)
1824 module_put(table_owner);
1825 xt_free_table_info(private);
1826 }
1827
1828 /* The built-in targets: standard (NULL) and error. */
1829 static struct xt_target arpt_builtin_tg[] __read_mostly = {
1830 {
1831 .name = XT_STANDARD_TARGET,
1832 .targetsize = sizeof(int),
1833 .family = NFPROTO_ARP,
1834 #ifdef CONFIG_COMPAT
1835 .compatsize = sizeof(compat_int_t),
1836 .compat_from_user = compat_standard_from_user,
1837 .compat_to_user = compat_standard_to_user,
1838 #endif
1839 },
1840 {
1841 .name = XT_ERROR_TARGET,
1842 .target = arpt_error,
1843 .targetsize = XT_FUNCTION_MAXNAMELEN,
1844 .family = NFPROTO_ARP,
1845 },
1846 };
1847
1848 static struct nf_sockopt_ops arpt_sockopts = {
1849 .pf = PF_INET,
1850 .set_optmin = ARPT_BASE_CTL,
1851 .set_optmax = ARPT_SO_SET_MAX+1,
1852 .set = do_arpt_set_ctl,
1853 #ifdef CONFIG_COMPAT
1854 .compat_set = compat_do_arpt_set_ctl,
1855 #endif
1856 .get_optmin = ARPT_BASE_CTL,
1857 .get_optmax = ARPT_SO_GET_MAX+1,
1858 .get = do_arpt_get_ctl,
1859 #ifdef CONFIG_COMPAT
1860 .compat_get = compat_do_arpt_get_ctl,
1861 #endif
1862 .owner = THIS_MODULE,
1863 };
1864
1865 static int __net_init arp_tables_net_init(struct net *net)
1866 {
1867 return xt_proto_init(net, NFPROTO_ARP);
1868 }
1869
1870 static void __net_exit arp_tables_net_exit(struct net *net)
1871 {
1872 xt_proto_fini(net, NFPROTO_ARP);
1873 }
1874
1875 static struct pernet_operations arp_tables_net_ops = {
1876 .init = arp_tables_net_init,
1877 .exit = arp_tables_net_exit,
1878 };
1879
1880 static int __init arp_tables_init(void)
1881 {
1882 int ret;
1883
1884 ret = register_pernet_subsys(&arp_tables_net_ops);
1885 if (ret < 0)
1886 goto err1;
1887
1888 /* No one else will be downing sem now, so we won't sleep */
1889 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1890 if (ret < 0)
1891 goto err2;
1892
1893 /* Register setsockopt */
1894 ret = nf_register_sockopt(&arpt_sockopts);
1895 if (ret < 0)
1896 goto err4;
1897
1898 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1899 return 0;
1900
1901 err4:
1902 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1903 err2:
1904 unregister_pernet_subsys(&arp_tables_net_ops);
1905 err1:
1906 return ret;
1907 }
1908
1909 static void __exit arp_tables_fini(void)
1910 {
1911 nf_unregister_sockopt(&arpt_sockopts);
1912 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1913 unregister_pernet_subsys(&arp_tables_net_ops);
1914 }
1915
1916 EXPORT_SYMBOL(arpt_register_table);
1917 EXPORT_SYMBOL(arpt_unregister_table);
1918 EXPORT_SYMBOL(arpt_do_table);
1919
1920 module_init(arp_tables_init);
1921 module_exit(arp_tables_fini);
Linux kernel - Deliverables
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