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Merge tag 'v3.10.102' into update
[GitHub/mt8127/android_kernel_alcatel_ttab.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 table_base = private->entries[smp_processor_id()];
275
276 e = get_entry(table_base, private->hook_entry[hook]);
277 back = get_entry(table_base, private->underflow[hook]);
278
279 acpar.in = in;
280 acpar.out = out;
281 acpar.hooknum = hook;
282 acpar.family = NFPROTO_ARP;
283 acpar.hotdrop = false;
284
285 arp = arp_hdr(skb);
286 do {
287 const struct xt_entry_target *t;
288
289 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
290 e = arpt_next_entry(e);
291 continue;
292 }
293
294 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
295
296 t = arpt_get_target_c(e);
297
298 /* Standard target? */
299 if (!t->u.kernel.target->target) {
300 int v;
301
302 v = ((struct xt_standard_target *)t)->verdict;
303 if (v < 0) {
304 /* Pop from stack? */
305 if (v != XT_RETURN) {
306 verdict = (unsigned int)(-v) - 1;
307 break;
308 }
309 e = back;
310 back = get_entry(table_base, back->comefrom);
311 continue;
312 }
313 if (table_base + v
314 != arpt_next_entry(e)) {
315 /* Save old back ptr in next entry */
316 struct arpt_entry *next = arpt_next_entry(e);
317 next->comefrom = (void *)back - table_base;
318
319 /* set back pointer to next entry */
320 back = next;
321 }
322
323 e = get_entry(table_base, v);
324 continue;
325 }
326
327 /* Targets which reenter must return
328 * abs. verdicts
329 */
330 acpar.target = t->u.kernel.target;
331 acpar.targinfo = t->data;
332 verdict = t->u.kernel.target->target(skb, &acpar);
333
334 /* Target might have changed stuff. */
335 arp = arp_hdr(skb);
336
337 if (verdict == XT_CONTINUE)
338 e = arpt_next_entry(e);
339 else
340 /* Verdict */
341 break;
342 } while (!acpar.hotdrop);
343 xt_write_recseq_end(addend);
344 local_bh_enable();
345
346 if (acpar.hotdrop)
347 return NF_DROP;
348 else
349 return verdict;
350 }
351
352 /* All zeroes == unconditional rule. */
353 static inline bool unconditional(const struct arpt_entry *e)
354 {
355 static const struct arpt_arp uncond;
356
357 return e->target_offset == sizeof(struct arpt_entry) &&
358 memcmp(&e->arp, &uncond, sizeof(uncond)) == 0;
359 }
360
361 /* Figures out from what hook each rule can be called: returns 0 if
362 * there are loops. Puts hook bitmask in comefrom.
363 */
364 static int mark_source_chains(const struct xt_table_info *newinfo,
365 unsigned int valid_hooks, void *entry0)
366 {
367 unsigned int hook;
368
369 /* No recursion; use packet counter to save back ptrs (reset
370 * to 0 as we leave), and comefrom to save source hook bitmask.
371 */
372 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
373 unsigned int pos = newinfo->hook_entry[hook];
374 struct arpt_entry *e
375 = (struct arpt_entry *)(entry0 + pos);
376
377 if (!(valid_hooks & (1 << hook)))
378 continue;
379
380 /* Set initial back pointer. */
381 e->counters.pcnt = pos;
382
383 for (;;) {
384 const struct xt_standard_target *t
385 = (void *)arpt_get_target_c(e);
386 int visited = e->comefrom & (1 << hook);
387
388 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
389 pr_notice("arptables: loop hook %u pos %u %08X.\n",
390 hook, pos, e->comefrom);
391 return 0;
392 }
393 e->comefrom
394 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
395
396 /* Unconditional return/END. */
397 if ((unconditional(e) &&
398 (strcmp(t->target.u.user.name,
399 XT_STANDARD_TARGET) == 0) &&
400 t->verdict < 0) || visited) {
401 unsigned int oldpos, size;
402
403 if ((strcmp(t->target.u.user.name,
404 XT_STANDARD_TARGET) == 0) &&
405 t->verdict < -NF_MAX_VERDICT - 1) {
406 duprintf("mark_source_chains: bad "
407 "negative verdict (%i)\n",
408 t->verdict);
409 return 0;
410 }
411
412 /* Return: backtrack through the last
413 * big jump.
414 */
415 do {
416 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
417 oldpos = pos;
418 pos = e->counters.pcnt;
419 e->counters.pcnt = 0;
420
421 /* We're at the start. */
422 if (pos == oldpos)
423 goto next;
424
425 e = (struct arpt_entry *)
426 (entry0 + pos);
427 } while (oldpos == pos + e->next_offset);
428
429 /* Move along one */
430 size = e->next_offset;
431 e = (struct arpt_entry *)
432 (entry0 + pos + size);
433 e->counters.pcnt = pos;
434 pos += size;
435 } else {
436 int newpos = t->verdict;
437
438 if (strcmp(t->target.u.user.name,
439 XT_STANDARD_TARGET) == 0 &&
440 newpos >= 0) {
441 if (newpos > newinfo->size -
442 sizeof(struct arpt_entry)) {
443 duprintf("mark_source_chains: "
444 "bad verdict (%i)\n",
445 newpos);
446 return 0;
447 }
448
449 /* This a jump; chase it. */
450 duprintf("Jump rule %u -> %u\n",
451 pos, newpos);
452 } else {
453 /* ... this is a fallthru */
454 newpos = pos + e->next_offset;
455 }
456 e = (struct arpt_entry *)
457 (entry0 + newpos);
458 e->counters.pcnt = pos;
459 pos = newpos;
460 }
461 }
462 next:
463 duprintf("Finished chain %u\n", hook);
464 }
465 return 1;
466 }
467
468 static inline int check_entry(const struct arpt_entry *e)
469 {
470 const struct xt_entry_target *t;
471
472 if (!arp_checkentry(&e->arp))
473 return -EINVAL;
474
475 if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
476 return -EINVAL;
477
478 t = arpt_get_target_c(e);
479 if (e->target_offset + t->u.target_size > e->next_offset)
480 return -EINVAL;
481
482 return 0;
483 }
484
485
486 static 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
508 static inline int
509 find_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 t = arpt_get_target(e);
516 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
517 t->u.user.revision);
518 if (IS_ERR(target)) {
519 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
520 ret = PTR_ERR(target);
521 goto out;
522 }
523 t->u.kernel.target = target;
524
525 ret = check_target(e, name);
526 if (ret)
527 goto err;
528 return 0;
529 err:
530 module_put(t->u.kernel.target->me);
531 out:
532 return ret;
533 }
534
535 static bool check_underflow(const struct arpt_entry *e)
536 {
537 const struct xt_entry_target *t;
538 unsigned int verdict;
539
540 if (!unconditional(e))
541 return false;
542 t = arpt_get_target_c(e);
543 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
544 return false;
545 verdict = ((struct xt_standard_target *)t)->verdict;
546 verdict = -verdict - 1;
547 return verdict == NF_DROP || verdict == NF_ACCEPT;
548 }
549
550 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
551 struct xt_table_info *newinfo,
552 const unsigned char *base,
553 const unsigned char *limit,
554 const unsigned int *hook_entries,
555 const unsigned int *underflows,
556 unsigned int valid_hooks)
557 {
558 unsigned int h;
559 int err;
560
561 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
562 (unsigned char *)e + sizeof(struct arpt_entry) >= limit ||
563 (unsigned char *)e + e->next_offset > limit) {
564 duprintf("Bad offset %p\n", e);
565 return -EINVAL;
566 }
567
568 if (e->next_offset
569 < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) {
570 duprintf("checking: element %p size %u\n",
571 e, e->next_offset);
572 return -EINVAL;
573 }
574
575 err = check_entry(e);
576 if (err)
577 return err;
578
579 /* Check hooks & underflows */
580 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
581 if (!(valid_hooks & (1 << h)))
582 continue;
583 if ((unsigned char *)e - base == hook_entries[h])
584 newinfo->hook_entry[h] = hook_entries[h];
585 if ((unsigned char *)e - base == underflows[h]) {
586 if (!check_underflow(e)) {
587 pr_err("Underflows must be unconditional and "
588 "use the STANDARD target with "
589 "ACCEPT/DROP\n");
590 return -EINVAL;
591 }
592 newinfo->underflow[h] = underflows[h];
593 }
594 }
595
596 /* Clear counters and comefrom */
597 e->counters = ((struct xt_counters) { 0, 0 });
598 e->comefrom = 0;
599 return 0;
600 }
601
602 static inline void cleanup_entry(struct arpt_entry *e)
603 {
604 struct xt_tgdtor_param par;
605 struct xt_entry_target *t;
606
607 t = arpt_get_target(e);
608 par.target = t->u.kernel.target;
609 par.targinfo = t->data;
610 par.family = NFPROTO_ARP;
611 if (par.target->destroy != NULL)
612 par.target->destroy(&par);
613 module_put(par.target->me);
614 }
615
616 /* Checks and translates the user-supplied table segment (held in
617 * newinfo).
618 */
619 static int translate_table(struct xt_table_info *newinfo, void *entry0,
620 const struct arpt_replace *repl)
621 {
622 struct arpt_entry *iter;
623 unsigned int i;
624 int ret = 0;
625
626 newinfo->size = repl->size;
627 newinfo->number = repl->num_entries;
628
629 /* Init all hooks to impossible value. */
630 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
631 newinfo->hook_entry[i] = 0xFFFFFFFF;
632 newinfo->underflow[i] = 0xFFFFFFFF;
633 }
634
635 duprintf("translate_table: size %u\n", newinfo->size);
636 i = 0;
637
638 /* Walk through entries, checking offsets. */
639 xt_entry_foreach(iter, entry0, newinfo->size) {
640 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
641 entry0 + repl->size,
642 repl->hook_entry,
643 repl->underflow,
644 repl->valid_hooks);
645 if (ret != 0)
646 break;
647 ++i;
648 if (strcmp(arpt_get_target(iter)->u.user.name,
649 XT_ERROR_TARGET) == 0)
650 ++newinfo->stacksize;
651 }
652 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
653 if (ret != 0)
654 return ret;
655
656 if (i != repl->num_entries) {
657 duprintf("translate_table: %u not %u entries\n",
658 i, repl->num_entries);
659 return -EINVAL;
660 }
661
662 /* Check hooks all assigned */
663 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
664 /* Only hooks which are valid */
665 if (!(repl->valid_hooks & (1 << i)))
666 continue;
667 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
668 duprintf("Invalid hook entry %u %u\n",
669 i, repl->hook_entry[i]);
670 return -EINVAL;
671 }
672 if (newinfo->underflow[i] == 0xFFFFFFFF) {
673 duprintf("Invalid underflow %u %u\n",
674 i, repl->underflow[i]);
675 return -EINVAL;
676 }
677 }
678
679 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
680 duprintf("Looping hook\n");
681 return -ELOOP;
682 }
683
684 /* Finally, each sanity check must pass */
685 i = 0;
686 xt_entry_foreach(iter, entry0, newinfo->size) {
687 ret = find_check_entry(iter, repl->name, repl->size);
688 if (ret != 0)
689 break;
690 ++i;
691 }
692
693 if (ret != 0) {
694 xt_entry_foreach(iter, entry0, newinfo->size) {
695 if (i-- == 0)
696 break;
697 cleanup_entry(iter);
698 }
699 return ret;
700 }
701
702 /* And one copy for every other CPU */
703 for_each_possible_cpu(i) {
704 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
705 memcpy(newinfo->entries[i], entry0, newinfo->size);
706 }
707
708 return ret;
709 }
710
711 static void get_counters(const struct xt_table_info *t,
712 struct xt_counters counters[])
713 {
714 struct arpt_entry *iter;
715 unsigned int cpu;
716 unsigned int i;
717
718 for_each_possible_cpu(cpu) {
719 seqcount_t *s = &per_cpu(xt_recseq, cpu);
720
721 i = 0;
722 xt_entry_foreach(iter, t->entries[cpu], t->size) {
723 u64 bcnt, pcnt;
724 unsigned int start;
725
726 do {
727 start = read_seqcount_begin(s);
728 bcnt = iter->counters.bcnt;
729 pcnt = iter->counters.pcnt;
730 } while (read_seqcount_retry(s, start));
731
732 ADD_COUNTER(counters[i], bcnt, pcnt);
733 ++i;
734 }
735 }
736 }
737
738 static struct xt_counters *alloc_counters(const struct xt_table *table)
739 {
740 unsigned int countersize;
741 struct xt_counters *counters;
742 const struct xt_table_info *private = table->private;
743
744 /* We need atomic snapshot of counters: rest doesn't change
745 * (other than comefrom, which userspace doesn't care
746 * about).
747 */
748 countersize = sizeof(struct xt_counters) * private->number;
749 counters = vzalloc(countersize);
750
751 if (counters == NULL)
752 return ERR_PTR(-ENOMEM);
753
754 get_counters(private, counters);
755
756 return counters;
757 }
758
759 static int copy_entries_to_user(unsigned int total_size,
760 const struct xt_table *table,
761 void __user *userptr)
762 {
763 unsigned int off, num;
764 const struct arpt_entry *e;
765 struct xt_counters *counters;
766 struct xt_table_info *private = table->private;
767 int ret = 0;
768 void *loc_cpu_entry;
769
770 counters = alloc_counters(table);
771 if (IS_ERR(counters))
772 return PTR_ERR(counters);
773
774 loc_cpu_entry = private->entries[raw_smp_processor_id()];
775 /* ... then copy entire thing ... */
776 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
777 ret = -EFAULT;
778 goto free_counters;
779 }
780
781 /* FIXME: use iterator macros --RR */
782 /* ... then go back and fix counters and names */
783 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
784 const struct xt_entry_target *t;
785
786 e = (struct arpt_entry *)(loc_cpu_entry + off);
787 if (copy_to_user(userptr + off
788 + offsetof(struct arpt_entry, counters),
789 &counters[num],
790 sizeof(counters[num])) != 0) {
791 ret = -EFAULT;
792 goto free_counters;
793 }
794
795 t = arpt_get_target_c(e);
796 if (copy_to_user(userptr + off + e->target_offset
797 + offsetof(struct xt_entry_target,
798 u.user.name),
799 t->u.kernel.target->name,
800 strlen(t->u.kernel.target->name)+1) != 0) {
801 ret = -EFAULT;
802 goto free_counters;
803 }
804 }
805
806 free_counters:
807 vfree(counters);
808 return ret;
809 }
810
811 #ifdef CONFIG_COMPAT
812 static void compat_standard_from_user(void *dst, const void *src)
813 {
814 int v = *(compat_int_t *)src;
815
816 if (v > 0)
817 v += xt_compat_calc_jump(NFPROTO_ARP, v);
818 memcpy(dst, &v, sizeof(v));
819 }
820
821 static int compat_standard_to_user(void __user *dst, const void *src)
822 {
823 compat_int_t cv = *(int *)src;
824
825 if (cv > 0)
826 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
827 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
828 }
829
830 static int compat_calc_entry(const struct arpt_entry *e,
831 const struct xt_table_info *info,
832 const void *base, struct xt_table_info *newinfo)
833 {
834 const struct xt_entry_target *t;
835 unsigned int entry_offset;
836 int off, i, ret;
837
838 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
839 entry_offset = (void *)e - base;
840
841 t = arpt_get_target_c(e);
842 off += xt_compat_target_offset(t->u.kernel.target);
843 newinfo->size -= off;
844 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
845 if (ret)
846 return ret;
847
848 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
849 if (info->hook_entry[i] &&
850 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
851 newinfo->hook_entry[i] -= off;
852 if (info->underflow[i] &&
853 (e < (struct arpt_entry *)(base + info->underflow[i])))
854 newinfo->underflow[i] -= off;
855 }
856 return 0;
857 }
858
859 static int compat_table_info(const struct xt_table_info *info,
860 struct xt_table_info *newinfo)
861 {
862 struct arpt_entry *iter;
863 void *loc_cpu_entry;
864 int ret;
865
866 if (!newinfo || !info)
867 return -EINVAL;
868
869 /* we dont care about newinfo->entries[] */
870 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
871 newinfo->initial_entries = 0;
872 loc_cpu_entry = info->entries[raw_smp_processor_id()];
873 xt_compat_init_offsets(NFPROTO_ARP, info->number);
874 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
875 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
876 if (ret != 0)
877 return ret;
878 }
879 return 0;
880 }
881 #endif
882
883 static int get_info(struct net *net, void __user *user,
884 const int *len, int compat)
885 {
886 char name[XT_TABLE_MAXNAMELEN];
887 struct xt_table *t;
888 int ret;
889
890 if (*len != sizeof(struct arpt_getinfo)) {
891 duprintf("length %u != %Zu\n", *len,
892 sizeof(struct arpt_getinfo));
893 return -EINVAL;
894 }
895
896 if (copy_from_user(name, user, sizeof(name)) != 0)
897 return -EFAULT;
898
899 name[XT_TABLE_MAXNAMELEN-1] = '\0';
900 #ifdef CONFIG_COMPAT
901 if (compat)
902 xt_compat_lock(NFPROTO_ARP);
903 #endif
904 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
905 "arptable_%s", name);
906 if (!IS_ERR_OR_NULL(t)) {
907 struct arpt_getinfo info;
908 const struct xt_table_info *private = t->private;
909 #ifdef CONFIG_COMPAT
910 struct xt_table_info tmp;
911
912 if (compat) {
913 ret = compat_table_info(private, &tmp);
914 xt_compat_flush_offsets(NFPROTO_ARP);
915 private = &tmp;
916 }
917 #endif
918 memset(&info, 0, sizeof(info));
919 info.valid_hooks = t->valid_hooks;
920 memcpy(info.hook_entry, private->hook_entry,
921 sizeof(info.hook_entry));
922 memcpy(info.underflow, private->underflow,
923 sizeof(info.underflow));
924 info.num_entries = private->number;
925 info.size = private->size;
926 strcpy(info.name, name);
927
928 if (copy_to_user(user, &info, *len) != 0)
929 ret = -EFAULT;
930 else
931 ret = 0;
932 xt_table_unlock(t);
933 module_put(t->me);
934 } else
935 ret = t ? PTR_ERR(t) : -ENOENT;
936 #ifdef CONFIG_COMPAT
937 if (compat)
938 xt_compat_unlock(NFPROTO_ARP);
939 #endif
940 return ret;
941 }
942
943 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
944 const int *len)
945 {
946 int ret;
947 struct arpt_get_entries get;
948 struct xt_table *t;
949
950 if (*len < sizeof(get)) {
951 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
952 return -EINVAL;
953 }
954 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
955 return -EFAULT;
956 if (*len != sizeof(struct arpt_get_entries) + get.size) {
957 duprintf("get_entries: %u != %Zu\n", *len,
958 sizeof(struct arpt_get_entries) + get.size);
959 return -EINVAL;
960 }
961
962 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
963 if (!IS_ERR_OR_NULL(t)) {
964 const struct xt_table_info *private = t->private;
965
966 duprintf("t->private->number = %u\n",
967 private->number);
968 if (get.size == private->size)
969 ret = copy_entries_to_user(private->size,
970 t, uptr->entrytable);
971 else {
972 duprintf("get_entries: I've got %u not %u!\n",
973 private->size, get.size);
974 ret = -EAGAIN;
975 }
976 module_put(t->me);
977 xt_table_unlock(t);
978 } else
979 ret = t ? PTR_ERR(t) : -ENOENT;
980
981 return ret;
982 }
983
984 static int __do_replace(struct net *net, const char *name,
985 unsigned int valid_hooks,
986 struct xt_table_info *newinfo,
987 unsigned int num_counters,
988 void __user *counters_ptr)
989 {
990 int ret;
991 struct xt_table *t;
992 struct xt_table_info *oldinfo;
993 struct xt_counters *counters;
994 void *loc_cpu_old_entry;
995 struct arpt_entry *iter;
996
997 ret = 0;
998 counters = vzalloc(num_counters * sizeof(struct xt_counters));
999 if (!counters) {
1000 ret = -ENOMEM;
1001 goto out;
1002 }
1003
1004 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1005 "arptable_%s", name);
1006 if (IS_ERR_OR_NULL(t)) {
1007 ret = t ? PTR_ERR(t) : -ENOENT;
1008 goto free_newinfo_counters_untrans;
1009 }
1010
1011 /* You lied! */
1012 if (valid_hooks != t->valid_hooks) {
1013 duprintf("Valid hook crap: %08X vs %08X\n",
1014 valid_hooks, t->valid_hooks);
1015 ret = -EINVAL;
1016 goto put_module;
1017 }
1018
1019 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1020 if (!oldinfo)
1021 goto put_module;
1022
1023 /* Update module usage count based on number of rules */
1024 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1025 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1026 if ((oldinfo->number > oldinfo->initial_entries) ||
1027 (newinfo->number <= oldinfo->initial_entries))
1028 module_put(t->me);
1029 if ((oldinfo->number > oldinfo->initial_entries) &&
1030 (newinfo->number <= oldinfo->initial_entries))
1031 module_put(t->me);
1032
1033 /* Get the old counters, and synchronize with replace */
1034 get_counters(oldinfo, counters);
1035
1036 /* Decrease module usage counts and free resource */
1037 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1038 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1039 cleanup_entry(iter);
1040
1041 xt_free_table_info(oldinfo);
1042 if (copy_to_user(counters_ptr, counters,
1043 sizeof(struct xt_counters) * num_counters) != 0) {
1044 /* Silent error, can't fail, new table is already in place */
1045 net_warn_ratelimited("arptables: counters copy to user failed while replacing table\n");
1046 }
1047 vfree(counters);
1048 xt_table_unlock(t);
1049 return ret;
1050
1051 put_module:
1052 module_put(t->me);
1053 xt_table_unlock(t);
1054 free_newinfo_counters_untrans:
1055 vfree(counters);
1056 out:
1057 return ret;
1058 }
1059
1060 static int do_replace(struct net *net, const void __user *user,
1061 unsigned int len)
1062 {
1063 int ret;
1064 struct arpt_replace tmp;
1065 struct xt_table_info *newinfo;
1066 void *loc_cpu_entry;
1067 struct arpt_entry *iter;
1068
1069 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1070 return -EFAULT;
1071
1072 /* overflow check */
1073 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1074 return -ENOMEM;
1075 tmp.name[sizeof(tmp.name)-1] = 0;
1076
1077 newinfo = xt_alloc_table_info(tmp.size);
1078 if (!newinfo)
1079 return -ENOMEM;
1080
1081 /* choose the copy that is on our node/cpu */
1082 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1083 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1084 tmp.size) != 0) {
1085 ret = -EFAULT;
1086 goto free_newinfo;
1087 }
1088
1089 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1090 if (ret != 0)
1091 goto free_newinfo;
1092
1093 duprintf("arp_tables: Translated table\n");
1094
1095 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1096 tmp.num_counters, tmp.counters);
1097 if (ret)
1098 goto free_newinfo_untrans;
1099 return 0;
1100
1101 free_newinfo_untrans:
1102 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1103 cleanup_entry(iter);
1104 free_newinfo:
1105 xt_free_table_info(newinfo);
1106 return ret;
1107 }
1108
1109 static int do_add_counters(struct net *net, const void __user *user,
1110 unsigned int len, int compat)
1111 {
1112 unsigned int i, curcpu;
1113 struct xt_counters_info tmp;
1114 struct xt_counters *paddc;
1115 unsigned int num_counters;
1116 const char *name;
1117 int size;
1118 void *ptmp;
1119 struct xt_table *t;
1120 const struct xt_table_info *private;
1121 int ret = 0;
1122 void *loc_cpu_entry;
1123 struct arpt_entry *iter;
1124 unsigned int addend;
1125 #ifdef CONFIG_COMPAT
1126 struct compat_xt_counters_info compat_tmp;
1127
1128 if (compat) {
1129 ptmp = &compat_tmp;
1130 size = sizeof(struct compat_xt_counters_info);
1131 } else
1132 #endif
1133 {
1134 ptmp = &tmp;
1135 size = sizeof(struct xt_counters_info);
1136 }
1137
1138 if (copy_from_user(ptmp, user, size) != 0)
1139 return -EFAULT;
1140
1141 #ifdef CONFIG_COMPAT
1142 if (compat) {
1143 num_counters = compat_tmp.num_counters;
1144 name = compat_tmp.name;
1145 } else
1146 #endif
1147 {
1148 num_counters = tmp.num_counters;
1149 name = tmp.name;
1150 }
1151
1152 if (len != size + num_counters * sizeof(struct xt_counters))
1153 return -EINVAL;
1154
1155 paddc = vmalloc(len - size);
1156 if (!paddc)
1157 return -ENOMEM;
1158
1159 if (copy_from_user(paddc, user + size, len - size) != 0) {
1160 ret = -EFAULT;
1161 goto free;
1162 }
1163
1164 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1165 if (IS_ERR_OR_NULL(t)) {
1166 ret = t ? PTR_ERR(t) : -ENOENT;
1167 goto free;
1168 }
1169
1170 local_bh_disable();
1171 private = t->private;
1172 if (private->number != num_counters) {
1173 ret = -EINVAL;
1174 goto unlock_up_free;
1175 }
1176
1177 i = 0;
1178 /* Choose the copy that is on our node */
1179 curcpu = smp_processor_id();
1180 loc_cpu_entry = private->entries[curcpu];
1181 addend = xt_write_recseq_begin();
1182 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1183 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1184 ++i;
1185 }
1186 xt_write_recseq_end(addend);
1187 unlock_up_free:
1188 local_bh_enable();
1189 xt_table_unlock(t);
1190 module_put(t->me);
1191 free:
1192 vfree(paddc);
1193
1194 return ret;
1195 }
1196
1197 #ifdef CONFIG_COMPAT
1198 static inline void compat_release_entry(struct compat_arpt_entry *e)
1199 {
1200 struct xt_entry_target *t;
1201
1202 t = compat_arpt_get_target(e);
1203 module_put(t->u.kernel.target->me);
1204 }
1205
1206 static inline int
1207 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1208 struct xt_table_info *newinfo,
1209 unsigned int *size,
1210 const unsigned char *base,
1211 const unsigned char *limit,
1212 const unsigned int *hook_entries,
1213 const unsigned int *underflows,
1214 const char *name)
1215 {
1216 struct xt_entry_target *t;
1217 struct xt_target *target;
1218 unsigned int entry_offset;
1219 int ret, off, h;
1220
1221 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1222 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1223 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit ||
1224 (unsigned char *)e + e->next_offset > limit) {
1225 duprintf("Bad offset %p, limit = %p\n", e, limit);
1226 return -EINVAL;
1227 }
1228
1229 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1230 sizeof(struct compat_xt_entry_target)) {
1231 duprintf("checking: element %p size %u\n",
1232 e, e->next_offset);
1233 return -EINVAL;
1234 }
1235
1236 /* For purposes of check_entry casting the compat entry is fine */
1237 ret = check_entry((struct arpt_entry *)e);
1238 if (ret)
1239 return ret;
1240
1241 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1242 entry_offset = (void *)e - (void *)base;
1243
1244 t = compat_arpt_get_target(e);
1245 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1246 t->u.user.revision);
1247 if (IS_ERR(target)) {
1248 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1249 t->u.user.name);
1250 ret = PTR_ERR(target);
1251 goto out;
1252 }
1253 t->u.kernel.target = target;
1254
1255 off += xt_compat_target_offset(target);
1256 *size += off;
1257 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1258 if (ret)
1259 goto release_target;
1260
1261 /* Check hooks & underflows */
1262 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1263 if ((unsigned char *)e - base == hook_entries[h])
1264 newinfo->hook_entry[h] = hook_entries[h];
1265 if ((unsigned char *)e - base == underflows[h])
1266 newinfo->underflow[h] = underflows[h];
1267 }
1268
1269 /* Clear counters and comefrom */
1270 memset(&e->counters, 0, sizeof(e->counters));
1271 e->comefrom = 0;
1272 return 0;
1273
1274 release_target:
1275 module_put(t->u.kernel.target->me);
1276 out:
1277 return ret;
1278 }
1279
1280 static int
1281 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1282 unsigned int *size, const char *name,
1283 struct xt_table_info *newinfo, unsigned char *base)
1284 {
1285 struct xt_entry_target *t;
1286 struct xt_target *target;
1287 struct arpt_entry *de;
1288 unsigned int origsize;
1289 int ret, h;
1290
1291 ret = 0;
1292 origsize = *size;
1293 de = (struct arpt_entry *)*dstptr;
1294 memcpy(de, e, sizeof(struct arpt_entry));
1295 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1296
1297 *dstptr += sizeof(struct arpt_entry);
1298 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1299
1300 de->target_offset = e->target_offset - (origsize - *size);
1301 t = compat_arpt_get_target(e);
1302 target = t->u.kernel.target;
1303 xt_compat_target_from_user(t, dstptr, size);
1304
1305 de->next_offset = e->next_offset - (origsize - *size);
1306 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1307 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1308 newinfo->hook_entry[h] -= origsize - *size;
1309 if ((unsigned char *)de - base < newinfo->underflow[h])
1310 newinfo->underflow[h] -= origsize - *size;
1311 }
1312 return ret;
1313 }
1314
1315 static int translate_compat_table(const char *name,
1316 unsigned int valid_hooks,
1317 struct xt_table_info **pinfo,
1318 void **pentry0,
1319 unsigned int total_size,
1320 unsigned int number,
1321 unsigned int *hook_entries,
1322 unsigned int *underflows)
1323 {
1324 unsigned int i, j;
1325 struct xt_table_info *newinfo, *info;
1326 void *pos, *entry0, *entry1;
1327 struct compat_arpt_entry *iter0;
1328 struct arpt_entry *iter1;
1329 unsigned int size;
1330 int ret = 0;
1331
1332 info = *pinfo;
1333 entry0 = *pentry0;
1334 size = total_size;
1335 info->number = number;
1336
1337 /* Init all hooks to impossible value. */
1338 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1339 info->hook_entry[i] = 0xFFFFFFFF;
1340 info->underflow[i] = 0xFFFFFFFF;
1341 }
1342
1343 duprintf("translate_compat_table: size %u\n", info->size);
1344 j = 0;
1345 xt_compat_lock(NFPROTO_ARP);
1346 xt_compat_init_offsets(NFPROTO_ARP, number);
1347 /* Walk through entries, checking offsets. */
1348 xt_entry_foreach(iter0, entry0, total_size) {
1349 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1350 entry0,
1351 entry0 + total_size,
1352 hook_entries,
1353 underflows,
1354 name);
1355 if (ret != 0)
1356 goto out_unlock;
1357 ++j;
1358 }
1359
1360 ret = -EINVAL;
1361 if (j != number) {
1362 duprintf("translate_compat_table: %u not %u entries\n",
1363 j, number);
1364 goto out_unlock;
1365 }
1366
1367 /* Check hooks all assigned */
1368 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1369 /* Only hooks which are valid */
1370 if (!(valid_hooks & (1 << i)))
1371 continue;
1372 if (info->hook_entry[i] == 0xFFFFFFFF) {
1373 duprintf("Invalid hook entry %u %u\n",
1374 i, hook_entries[i]);
1375 goto out_unlock;
1376 }
1377 if (info->underflow[i] == 0xFFFFFFFF) {
1378 duprintf("Invalid underflow %u %u\n",
1379 i, underflows[i]);
1380 goto out_unlock;
1381 }
1382 }
1383
1384 ret = -ENOMEM;
1385 newinfo = xt_alloc_table_info(size);
1386 if (!newinfo)
1387 goto out_unlock;
1388
1389 newinfo->number = number;
1390 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1391 newinfo->hook_entry[i] = info->hook_entry[i];
1392 newinfo->underflow[i] = info->underflow[i];
1393 }
1394 entry1 = newinfo->entries[raw_smp_processor_id()];
1395 pos = entry1;
1396 size = total_size;
1397 xt_entry_foreach(iter0, entry0, total_size) {
1398 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1399 name, newinfo, entry1);
1400 if (ret != 0)
1401 break;
1402 }
1403 xt_compat_flush_offsets(NFPROTO_ARP);
1404 xt_compat_unlock(NFPROTO_ARP);
1405 if (ret)
1406 goto free_newinfo;
1407
1408 ret = -ELOOP;
1409 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1410 goto free_newinfo;
1411
1412 i = 0;
1413 xt_entry_foreach(iter1, entry1, newinfo->size) {
1414 ret = check_target(iter1, name);
1415 if (ret != 0)
1416 break;
1417 ++i;
1418 if (strcmp(arpt_get_target(iter1)->u.user.name,
1419 XT_ERROR_TARGET) == 0)
1420 ++newinfo->stacksize;
1421 }
1422 if (ret) {
1423 /*
1424 * The first i matches need cleanup_entry (calls ->destroy)
1425 * because they had called ->check already. The other j-i
1426 * entries need only release.
1427 */
1428 int skip = i;
1429 j -= i;
1430 xt_entry_foreach(iter0, entry0, newinfo->size) {
1431 if (skip-- > 0)
1432 continue;
1433 if (j-- == 0)
1434 break;
1435 compat_release_entry(iter0);
1436 }
1437 xt_entry_foreach(iter1, entry1, newinfo->size) {
1438 if (i-- == 0)
1439 break;
1440 cleanup_entry(iter1);
1441 }
1442 xt_free_table_info(newinfo);
1443 return ret;
1444 }
1445
1446 /* And one copy for every other CPU */
1447 for_each_possible_cpu(i)
1448 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1449 memcpy(newinfo->entries[i], entry1, newinfo->size);
1450
1451 *pinfo = newinfo;
1452 *pentry0 = entry1;
1453 xt_free_table_info(info);
1454 return 0;
1455
1456 free_newinfo:
1457 xt_free_table_info(newinfo);
1458 out:
1459 xt_entry_foreach(iter0, entry0, total_size) {
1460 if (j-- == 0)
1461 break;
1462 compat_release_entry(iter0);
1463 }
1464 return ret;
1465 out_unlock:
1466 xt_compat_flush_offsets(NFPROTO_ARP);
1467 xt_compat_unlock(NFPROTO_ARP);
1468 goto out;
1469 }
1470
1471 struct compat_arpt_replace {
1472 char name[XT_TABLE_MAXNAMELEN];
1473 u32 valid_hooks;
1474 u32 num_entries;
1475 u32 size;
1476 u32 hook_entry[NF_ARP_NUMHOOKS];
1477 u32 underflow[NF_ARP_NUMHOOKS];
1478 u32 num_counters;
1479 compat_uptr_t counters;
1480 struct compat_arpt_entry entries[0];
1481 };
1482
1483 static int compat_do_replace(struct net *net, void __user *user,
1484 unsigned int len)
1485 {
1486 int ret;
1487 struct compat_arpt_replace tmp;
1488 struct xt_table_info *newinfo;
1489 void *loc_cpu_entry;
1490 struct arpt_entry *iter;
1491
1492 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1493 return -EFAULT;
1494
1495 /* overflow check */
1496 if (tmp.size >= INT_MAX / num_possible_cpus())
1497 return -ENOMEM;
1498 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1499 return -ENOMEM;
1500 tmp.name[sizeof(tmp.name)-1] = 0;
1501
1502 newinfo = xt_alloc_table_info(tmp.size);
1503 if (!newinfo)
1504 return -ENOMEM;
1505
1506 /* choose the copy that is on our node/cpu */
1507 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1508 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1509 ret = -EFAULT;
1510 goto free_newinfo;
1511 }
1512
1513 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1514 &newinfo, &loc_cpu_entry, tmp.size,
1515 tmp.num_entries, tmp.hook_entry,
1516 tmp.underflow);
1517 if (ret != 0)
1518 goto free_newinfo;
1519
1520 duprintf("compat_do_replace: Translated table\n");
1521
1522 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1523 tmp.num_counters, compat_ptr(tmp.counters));
1524 if (ret)
1525 goto free_newinfo_untrans;
1526 return 0;
1527
1528 free_newinfo_untrans:
1529 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1530 cleanup_entry(iter);
1531 free_newinfo:
1532 xt_free_table_info(newinfo);
1533 return ret;
1534 }
1535
1536 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1537 unsigned int len)
1538 {
1539 int ret;
1540
1541 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1542 return -EPERM;
1543
1544 switch (cmd) {
1545 case ARPT_SO_SET_REPLACE:
1546 ret = compat_do_replace(sock_net(sk), user, len);
1547 break;
1548
1549 case ARPT_SO_SET_ADD_COUNTERS:
1550 ret = do_add_counters(sock_net(sk), user, len, 1);
1551 break;
1552
1553 default:
1554 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1555 ret = -EINVAL;
1556 }
1557
1558 return ret;
1559 }
1560
1561 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1562 compat_uint_t *size,
1563 struct xt_counters *counters,
1564 unsigned int i)
1565 {
1566 struct xt_entry_target *t;
1567 struct compat_arpt_entry __user *ce;
1568 u_int16_t target_offset, next_offset;
1569 compat_uint_t origsize;
1570 int ret;
1571
1572 origsize = *size;
1573 ce = (struct compat_arpt_entry __user *)*dstptr;
1574 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1575 copy_to_user(&ce->counters, &counters[i],
1576 sizeof(counters[i])) != 0)
1577 return -EFAULT;
1578
1579 *dstptr += sizeof(struct compat_arpt_entry);
1580 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1581
1582 target_offset = e->target_offset - (origsize - *size);
1583
1584 t = arpt_get_target(e);
1585 ret = xt_compat_target_to_user(t, dstptr, size);
1586 if (ret)
1587 return ret;
1588 next_offset = e->next_offset - (origsize - *size);
1589 if (put_user(target_offset, &ce->target_offset) != 0 ||
1590 put_user(next_offset, &ce->next_offset) != 0)
1591 return -EFAULT;
1592 return 0;
1593 }
1594
1595 static int compat_copy_entries_to_user(unsigned int total_size,
1596 struct xt_table *table,
1597 void __user *userptr)
1598 {
1599 struct xt_counters *counters;
1600 const struct xt_table_info *private = table->private;
1601 void __user *pos;
1602 unsigned int size;
1603 int ret = 0;
1604 void *loc_cpu_entry;
1605 unsigned int i = 0;
1606 struct arpt_entry *iter;
1607
1608 counters = alloc_counters(table);
1609 if (IS_ERR(counters))
1610 return PTR_ERR(counters);
1611
1612 /* choose the copy on our node/cpu */
1613 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1614 pos = userptr;
1615 size = total_size;
1616 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1617 ret = compat_copy_entry_to_user(iter, &pos,
1618 &size, counters, i++);
1619 if (ret != 0)
1620 break;
1621 }
1622 vfree(counters);
1623 return ret;
1624 }
1625
1626 struct compat_arpt_get_entries {
1627 char name[XT_TABLE_MAXNAMELEN];
1628 compat_uint_t size;
1629 struct compat_arpt_entry entrytable[0];
1630 };
1631
1632 static int compat_get_entries(struct net *net,
1633 struct compat_arpt_get_entries __user *uptr,
1634 int *len)
1635 {
1636 int ret;
1637 struct compat_arpt_get_entries get;
1638 struct xt_table *t;
1639
1640 if (*len < sizeof(get)) {
1641 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1642 return -EINVAL;
1643 }
1644 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1645 return -EFAULT;
1646 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1647 duprintf("compat_get_entries: %u != %zu\n",
1648 *len, sizeof(get) + get.size);
1649 return -EINVAL;
1650 }
1651
1652 xt_compat_lock(NFPROTO_ARP);
1653 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1654 if (!IS_ERR_OR_NULL(t)) {
1655 const struct xt_table_info *private = t->private;
1656 struct xt_table_info info;
1657
1658 duprintf("t->private->number = %u\n", private->number);
1659 ret = compat_table_info(private, &info);
1660 if (!ret && get.size == info.size) {
1661 ret = compat_copy_entries_to_user(private->size,
1662 t, uptr->entrytable);
1663 } else if (!ret) {
1664 duprintf("compat_get_entries: I've got %u not %u!\n",
1665 private->size, get.size);
1666 ret = -EAGAIN;
1667 }
1668 xt_compat_flush_offsets(NFPROTO_ARP);
1669 module_put(t->me);
1670 xt_table_unlock(t);
1671 } else
1672 ret = t ? PTR_ERR(t) : -ENOENT;
1673
1674 xt_compat_unlock(NFPROTO_ARP);
1675 return ret;
1676 }
1677
1678 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1679
1680 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1681 int *len)
1682 {
1683 int ret;
1684
1685 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1686 return -EPERM;
1687
1688 switch (cmd) {
1689 case ARPT_SO_GET_INFO:
1690 ret = get_info(sock_net(sk), user, len, 1);
1691 break;
1692 case ARPT_SO_GET_ENTRIES:
1693 ret = compat_get_entries(sock_net(sk), user, len);
1694 break;
1695 default:
1696 ret = do_arpt_get_ctl(sk, cmd, user, len);
1697 }
1698 return ret;
1699 }
1700 #endif
1701
1702 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1703 {
1704 int ret;
1705
1706 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1707 return -EPERM;
1708
1709 switch (cmd) {
1710 case ARPT_SO_SET_REPLACE:
1711 ret = do_replace(sock_net(sk), user, len);
1712 break;
1713
1714 case ARPT_SO_SET_ADD_COUNTERS:
1715 ret = do_add_counters(sock_net(sk), user, len, 0);
1716 break;
1717
1718 default:
1719 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1720 ret = -EINVAL;
1721 }
1722
1723 return ret;
1724 }
1725
1726 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1727 {
1728 int ret;
1729
1730 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1731 return -EPERM;
1732
1733 switch (cmd) {
1734 case ARPT_SO_GET_INFO:
1735 ret = get_info(sock_net(sk), user, len, 0);
1736 break;
1737
1738 case ARPT_SO_GET_ENTRIES:
1739 ret = get_entries(sock_net(sk), user, len);
1740 break;
1741
1742 case ARPT_SO_GET_REVISION_TARGET: {
1743 struct xt_get_revision rev;
1744
1745 if (*len != sizeof(rev)) {
1746 ret = -EINVAL;
1747 break;
1748 }
1749 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1750 ret = -EFAULT;
1751 break;
1752 }
1753 rev.name[sizeof(rev.name)-1] = 0;
1754
1755 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1756 rev.revision, 1, &ret),
1757 "arpt_%s", rev.name);
1758 break;
1759 }
1760
1761 default:
1762 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1763 ret = -EINVAL;
1764 }
1765
1766 return ret;
1767 }
1768
1769 struct xt_table *arpt_register_table(struct net *net,
1770 const struct xt_table *table,
1771 const struct arpt_replace *repl)
1772 {
1773 int ret;
1774 struct xt_table_info *newinfo;
1775 struct xt_table_info bootstrap = {0};
1776 void *loc_cpu_entry;
1777 struct xt_table *new_table;
1778
1779 newinfo = xt_alloc_table_info(repl->size);
1780 if (!newinfo) {
1781 ret = -ENOMEM;
1782 goto out;
1783 }
1784
1785 /* choose the copy on our node/cpu */
1786 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1787 memcpy(loc_cpu_entry, repl->entries, repl->size);
1788
1789 ret = translate_table(newinfo, loc_cpu_entry, repl);
1790 duprintf("arpt_register_table: translate table gives %d\n", ret);
1791 if (ret != 0)
1792 goto out_free;
1793
1794 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1795 if (IS_ERR(new_table)) {
1796 ret = PTR_ERR(new_table);
1797 goto out_free;
1798 }
1799 return new_table;
1800
1801 out_free:
1802 xt_free_table_info(newinfo);
1803 out:
1804 return ERR_PTR(ret);
1805 }
1806
1807 void arpt_unregister_table(struct xt_table *table)
1808 {
1809 struct xt_table_info *private;
1810 void *loc_cpu_entry;
1811 struct module *table_owner = table->me;
1812 struct arpt_entry *iter;
1813
1814 private = xt_unregister_table(table);
1815
1816 /* Decrease module usage counts and free resources */
1817 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1818 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1819 cleanup_entry(iter);
1820 if (private->number > private->initial_entries)
1821 module_put(table_owner);
1822 xt_free_table_info(private);
1823 }
1824
1825 /* The built-in targets: standard (NULL) and error. */
1826 static struct xt_target arpt_builtin_tg[] __read_mostly = {
1827 {
1828 .name = XT_STANDARD_TARGET,
1829 .targetsize = sizeof(int),
1830 .family = NFPROTO_ARP,
1831 #ifdef CONFIG_COMPAT
1832 .compatsize = sizeof(compat_int_t),
1833 .compat_from_user = compat_standard_from_user,
1834 .compat_to_user = compat_standard_to_user,
1835 #endif
1836 },
1837 {
1838 .name = XT_ERROR_TARGET,
1839 .target = arpt_error,
1840 .targetsize = XT_FUNCTION_MAXNAMELEN,
1841 .family = NFPROTO_ARP,
1842 },
1843 };
1844
1845 static struct nf_sockopt_ops arpt_sockopts = {
1846 .pf = PF_INET,
1847 .set_optmin = ARPT_BASE_CTL,
1848 .set_optmax = ARPT_SO_SET_MAX+1,
1849 .set = do_arpt_set_ctl,
1850 #ifdef CONFIG_COMPAT
1851 .compat_set = compat_do_arpt_set_ctl,
1852 #endif
1853 .get_optmin = ARPT_BASE_CTL,
1854 .get_optmax = ARPT_SO_GET_MAX+1,
1855 .get = do_arpt_get_ctl,
1856 #ifdef CONFIG_COMPAT
1857 .compat_get = compat_do_arpt_get_ctl,
1858 #endif
1859 .owner = THIS_MODULE,
1860 };
1861
1862 static int __net_init arp_tables_net_init(struct net *net)
1863 {
1864 return xt_proto_init(net, NFPROTO_ARP);
1865 }
1866
1867 static void __net_exit arp_tables_net_exit(struct net *net)
1868 {
1869 xt_proto_fini(net, NFPROTO_ARP);
1870 }
1871
1872 static struct pernet_operations arp_tables_net_ops = {
1873 .init = arp_tables_net_init,
1874 .exit = arp_tables_net_exit,
1875 };
1876
1877 static int __init arp_tables_init(void)
1878 {
1879 int ret;
1880
1881 ret = register_pernet_subsys(&arp_tables_net_ops);
1882 if (ret < 0)
1883 goto err1;
1884
1885 /* No one else will be downing sem now, so we won't sleep */
1886 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1887 if (ret < 0)
1888 goto err2;
1889
1890 /* Register setsockopt */
1891 ret = nf_register_sockopt(&arpt_sockopts);
1892 if (ret < 0)
1893 goto err4;
1894
1895 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1896 return 0;
1897
1898 err4:
1899 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1900 err2:
1901 unregister_pernet_subsys(&arp_tables_net_ops);
1902 err1:
1903 return ret;
1904 }
1905
1906 static void __exit arp_tables_fini(void)
1907 {
1908 nf_unregister_sockopt(&arpt_sockopts);
1909 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1910 unregister_pernet_subsys(&arp_tables_net_ops);
1911 }
1912
1913 EXPORT_SYMBOL(arpt_register_table);
1914 EXPORT_SYMBOL(arpt_unregister_table);
1915 EXPORT_SYMBOL(arpt_do_table);
1916
1917 module_init(arp_tables_init);
1918 module_exit(arp_tables_fini);
kernel source for telekom puls (alcatel/mediatek)