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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / net / ipv4 / netfilter / arp_tables.c
bloba7591ce344d2c18a747c717ded8fa96671e2dcc8
1 /*
2 * Packet matching code for ARP packets.
3 *
4 * Based heavily, if not almost entirely, upon ip_tables.c framework.
5 *
6 * Some ARP specific bits are:
7 *
8 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
9 *
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/capability.h>
16 #include <linux/if_arp.h>
17 #include <linux/kmod.h>
18 #include <linux/vmalloc.h>
19 #include <linux/proc_fs.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/mutex.h>
23 #include <linux/err.h>
24 #include <net/compat.h>
25 #include <net/sock.h>
26 #include <asm/uaccess.h>
27
28 #include <linux/netfilter/x_tables.h>
29 #include <linux/netfilter_arp/arp_tables.h>
30
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
33 MODULE_DESCRIPTION("arptables core");
34
35 /*#define DEBUG_ARP_TABLES*/
36 /*#define DEBUG_ARP_TABLES_USER*/
37
38 #ifdef DEBUG_ARP_TABLES
39 #define dprintf(format, args...) printk(format , ## args)
40 #else
41 #define dprintf(format, args...)
42 #endif
43
44 #ifdef DEBUG_ARP_TABLES_USER
45 #define duprintf(format, args...) printk(format , ## args)
46 #else
47 #define duprintf(format, args...)
48 #endif
49
50 #ifdef CONFIG_NETFILTER_DEBUG
51 #define ARP_NF_ASSERT(x) \
52 do { \
53 if (!(x)) \
54 printk("ARP_NF_ASSERT: %s:%s:%u\n", \
55 __FUNCTION__, __FILE__, __LINE__); \
56 } while(0)
57 #else
58 #define ARP_NF_ASSERT(x)
59 #endif
60
61 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
62 char *hdr_addr, int len)
63 {
64 int i, ret;
65
66 if (len > ARPT_DEV_ADDR_LEN_MAX)
67 len = ARPT_DEV_ADDR_LEN_MAX;
68
69 ret = 0;
70 for (i = 0; i < len; i++)
71 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
72
73 return (ret != 0);
74 }
75
76 /* Returns whether packet matches rule or not. */
77 static inline int arp_packet_match(const struct arphdr *arphdr,
78 struct net_device *dev,
79 const char *indev,
80 const char *outdev,
81 const struct arpt_arp *arpinfo)
82 {
83 char *arpptr = (char *)(arphdr + 1);
84 char *src_devaddr, *tgt_devaddr;
85 __be32 src_ipaddr, tgt_ipaddr;
86 int i, ret;
87
88 #define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
89
90 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
91 ARPT_INV_ARPOP)) {
92 dprintf("ARP operation field mismatch.\n");
93 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
94 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
95 return 0;
96 }
97
98 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
99 ARPT_INV_ARPHRD)) {
100 dprintf("ARP hardware address format mismatch.\n");
101 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
102 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
103 return 0;
104 }
105
106 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
107 ARPT_INV_ARPPRO)) {
108 dprintf("ARP protocol address format mismatch.\n");
109 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
110 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
111 return 0;
112 }
113
114 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
115 ARPT_INV_ARPHLN)) {
116 dprintf("ARP hardware address length mismatch.\n");
117 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
118 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
119 return 0;
120 }
121
122 src_devaddr = arpptr;
123 arpptr += dev->addr_len;
124 memcpy(&src_ipaddr, arpptr, sizeof(u32));
125 arpptr += sizeof(u32);
126 tgt_devaddr = arpptr;
127 arpptr += dev->addr_len;
128 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
129
130 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
131 ARPT_INV_SRCDEVADDR) ||
132 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
133 ARPT_INV_TGTDEVADDR)) {
134 dprintf("Source or target device address mismatch.\n");
135
136 return 0;
137 }
138
139 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
140 ARPT_INV_SRCIP) ||
141 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
142 ARPT_INV_TGTIP)) {
143 dprintf("Source or target IP address mismatch.\n");
144
145 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
146 NIPQUAD(src_ipaddr),
147 NIPQUAD(arpinfo->smsk.s_addr),
148 NIPQUAD(arpinfo->src.s_addr),
149 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
150 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
151 NIPQUAD(tgt_ipaddr),
152 NIPQUAD(arpinfo->tmsk.s_addr),
153 NIPQUAD(arpinfo->tgt.s_addr),
154 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
155 return 0;
156 }
157
158 /* Look for ifname matches. */
159 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
160 ret |= (indev[i] ^ arpinfo->iniface[i])
161 & arpinfo->iniface_mask[i];
162 }
163
164 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
165 dprintf("VIA in mismatch (%s vs %s).%s\n",
166 indev, arpinfo->iniface,
167 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
168 return 0;
169 }
170
171 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
172 ret |= (outdev[i] ^ arpinfo->outiface[i])
173 & arpinfo->outiface_mask[i];
174 }
175
176 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
177 dprintf("VIA out mismatch (%s vs %s).%s\n",
178 outdev, arpinfo->outiface,
179 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
180 return 0;
181 }
182
183 return 1;
184 #undef FWINV
185 }
186
187 static inline int arp_checkentry(const struct arpt_arp *arp)
188 {
189 if (arp->flags & ~ARPT_F_MASK) {
190 duprintf("Unknown flag bits set: %08X\n",
191 arp->flags & ~ARPT_F_MASK);
192 return 0;
193 }
194 if (arp->invflags & ~ARPT_INV_MASK) {
195 duprintf("Unknown invflag bits set: %08X\n",
196 arp->invflags & ~ARPT_INV_MASK);
197 return 0;
198 }
199
200 return 1;
201 }
202
203 static unsigned int arpt_error(struct sk_buff *skb,
204 const struct net_device *in,
205 const struct net_device *out,
206 unsigned int hooknum,
207 const struct xt_target *target,
208 const void *targinfo)
209 {
210 if (net_ratelimit())
211 printk("arp_tables: error: '%s'\n", (char *)targinfo);
212
213 return NF_DROP;
214 }
215
216 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
217 {
218 return (struct arpt_entry *)(base + offset);
219 }
220
221 unsigned int arpt_do_table(struct sk_buff *skb,
222 unsigned int hook,
223 const struct net_device *in,
224 const struct net_device *out,
225 struct arpt_table *table)
226 {
227 static const char nulldevname[IFNAMSIZ];
228 unsigned int verdict = NF_DROP;
229 struct arphdr *arp;
230 bool hotdrop = false;
231 struct arpt_entry *e, *back;
232 const char *indev, *outdev;
233 void *table_base;
234 struct xt_table_info *private;
235
236 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
237 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
238 (2 * skb->dev->addr_len) +
239 (2 * sizeof(u32)))))
240 return NF_DROP;
241
242 indev = in ? in->name : nulldevname;
243 outdev = out ? out->name : nulldevname;
244
245 read_lock_bh(&table->lock);
246 private = table->private;
247 table_base = (void *)private->entries[smp_processor_id()];
248 e = get_entry(table_base, private->hook_entry[hook]);
249 back = get_entry(table_base, private->underflow[hook]);
250
251 arp = arp_hdr(skb);
252 do {
253 if (arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
254 struct arpt_entry_target *t;
255 int hdr_len;
256
257 hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
258 (2 * skb->dev->addr_len);
259 ADD_COUNTER(e->counters, hdr_len, 1);
260
261 t = arpt_get_target(e);
262
263 /* Standard target? */
264 if (!t->u.kernel.target->target) {
265 int v;
266
267 v = ((struct arpt_standard_target *)t)->verdict;
268 if (v < 0) {
269 /* Pop from stack? */
270 if (v != ARPT_RETURN) {
271 verdict = (unsigned)(-v) - 1;
272 break;
273 }
274 e = back;
275 back = get_entry(table_base,
276 back->comefrom);
277 continue;
278 }
279 if (table_base + v
280 != (void *)e + e->next_offset) {
281 /* Save old back ptr in next entry */
282 struct arpt_entry *next
283 = (void *)e + e->next_offset;
284 next->comefrom =
285 (void *)back - table_base;
286
287 /* set back pointer to next entry */
288 back = next;
289 }
290
291 e = get_entry(table_base, v);
292 } else {
293 /* Targets which reenter must return
294 * abs. verdicts
295 */
296 verdict = t->u.kernel.target->target(skb,
297 in, out,
298 hook,
299 t->u.kernel.target,
300 t->data);
301
302 /* Target might have changed stuff. */
303 arp = arp_hdr(skb);
304
305 if (verdict == ARPT_CONTINUE)
306 e = (void *)e + e->next_offset;
307 else
308 /* Verdict */
309 break;
310 }
311 } else {
312 e = (void *)e + e->next_offset;
313 }
314 } while (!hotdrop);
315 read_unlock_bh(&table->lock);
316
317 if (hotdrop)
318 return NF_DROP;
319 else
320 return verdict;
321 }
322
323 /* All zeroes == unconditional rule. */
324 static inline int unconditional(const struct arpt_arp *arp)
325 {
326 unsigned int i;
327
328 for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
329 if (((__u32 *)arp)[i])
330 return 0;
331
332 return 1;
333 }
334
335 /* Figures out from what hook each rule can be called: returns 0 if
336 * there are loops. Puts hook bitmask in comefrom.
337 */
338 static int mark_source_chains(struct xt_table_info *newinfo,
339 unsigned int valid_hooks, void *entry0)
340 {
341 unsigned int hook;
342
343 /* No recursion; use packet counter to save back ptrs (reset
344 * to 0 as we leave), and comefrom to save source hook bitmask.
345 */
346 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
347 unsigned int pos = newinfo->hook_entry[hook];
348 struct arpt_entry *e
349 = (struct arpt_entry *)(entry0 + pos);
350
351 if (!(valid_hooks & (1 << hook)))
352 continue;
353
354 /* Set initial back pointer. */
355 e->counters.pcnt = pos;
356
357 for (;;) {
358 struct arpt_standard_target *t
359 = (void *)arpt_get_target(e);
360 int visited = e->comefrom & (1 << hook);
361
362 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
363 printk("arptables: loop hook %u pos %u %08X.\n",
364 hook, pos, e->comefrom);
365 return 0;
366 }
367 e->comefrom
368 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
369
370 /* Unconditional return/END. */
371 if ((e->target_offset == sizeof(struct arpt_entry)
372 && (strcmp(t->target.u.user.name,
373 ARPT_STANDARD_TARGET) == 0)
374 && t->verdict < 0
375 && unconditional(&e->arp)) || visited) {
376 unsigned int oldpos, size;
377
378 if (t->verdict < -NF_MAX_VERDICT - 1) {
379 duprintf("mark_source_chains: bad "
380 "negative verdict (%i)\n",
381 t->verdict);
382 return 0;
383 }
384
385 /* Return: backtrack through the last
386 * big jump.
387 */
388 do {
389 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
390 oldpos = pos;
391 pos = e->counters.pcnt;
392 e->counters.pcnt = 0;
393
394 /* We're at the start. */
395 if (pos == oldpos)
396 goto next;
397
398 e = (struct arpt_entry *)
399 (entry0 + pos);
400 } while (oldpos == pos + e->next_offset);
401
402 /* Move along one */
403 size = e->next_offset;
404 e = (struct arpt_entry *)
405 (entry0 + pos + size);
406 e->counters.pcnt = pos;
407 pos += size;
408 } else {
409 int newpos = t->verdict;
410
411 if (strcmp(t->target.u.user.name,
412 ARPT_STANDARD_TARGET) == 0
413 && newpos >= 0) {
414 if (newpos > newinfo->size -
415 sizeof(struct arpt_entry)) {
416 duprintf("mark_source_chains: "
417 "bad verdict (%i)\n",
418 newpos);
419 return 0;
420 }
421
422 /* This a jump; chase it. */
423 duprintf("Jump rule %u -> %u\n",
424 pos, newpos);
425 } else {
426 /* ... this is a fallthru */
427 newpos = pos + e->next_offset;
428 }
429 e = (struct arpt_entry *)
430 (entry0 + newpos);
431 e->counters.pcnt = pos;
432 pos = newpos;
433 }
434 }
435 next:
436 duprintf("Finished chain %u\n", hook);
437 }
438 return 1;
439 }
440
441 static inline int check_entry(struct arpt_entry *e, const char *name)
442 {
443 struct arpt_entry_target *t;
444
445 if (!arp_checkentry(&e->arp)) {
446 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
447 return -EINVAL;
448 }
449
450 if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset)
451 return -EINVAL;
452
453 t = arpt_get_target(e);
454 if (e->target_offset + t->u.target_size > e->next_offset)
455 return -EINVAL;
456
457 return 0;
458 }
459
460 static inline int check_target(struct arpt_entry *e, const char *name)
461 {
462 struct arpt_entry_target *t;
463 struct arpt_target *target;
464 int ret;
465
466 t = arpt_get_target(e);
467 target = t->u.kernel.target;
468
469 ret = xt_check_target(target, NF_ARP, t->u.target_size - sizeof(*t),
470 name, e->comefrom, 0, 0);
471 if (!ret && t->u.kernel.target->checkentry
472 && !t->u.kernel.target->checkentry(name, e, target, t->data,
473 e->comefrom)) {
474 duprintf("arp_tables: check failed for `%s'.\n",
475 t->u.kernel.target->name);
476 ret = -EINVAL;
477 }
478 return ret;
479 }
480
481 static inline int
482 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size,
483 unsigned int *i)
484 {
485 struct arpt_entry_target *t;
486 struct arpt_target *target;
487 int ret;
488
489 ret = check_entry(e, name);
490 if (ret)
491 return ret;
492
493 t = arpt_get_target(e);
494 target = try_then_request_module(xt_find_target(NF_ARP, t->u.user.name,
495 t->u.user.revision),
496 "arpt_%s", t->u.user.name);
497 if (IS_ERR(target) || !target) {
498 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
499 ret = target ? PTR_ERR(target) : -ENOENT;
500 goto out;
501 }
502 t->u.kernel.target = target;
503
504 ret = check_target(e, name);
505 if (ret)
506 goto err;
507
508 (*i)++;
509 return 0;
510 err:
511 module_put(t->u.kernel.target->me);
512 out:
513 return ret;
514 }
515
516 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
517 struct xt_table_info *newinfo,
518 unsigned char *base,
519 unsigned char *limit,
520 const unsigned int *hook_entries,
521 const unsigned int *underflows,
522 unsigned int *i)
523 {
524 unsigned int h;
525
526 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
527 || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
528 duprintf("Bad offset %p\n", e);
529 return -EINVAL;
530 }
531
532 if (e->next_offset
533 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
534 duprintf("checking: element %p size %u\n",
535 e, e->next_offset);
536 return -EINVAL;
537 }
538
539 /* Check hooks & underflows */
540 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
541 if ((unsigned char *)e - base == hook_entries[h])
542 newinfo->hook_entry[h] = hook_entries[h];
543 if ((unsigned char *)e - base == underflows[h])
544 newinfo->underflow[h] = underflows[h];
545 }
546
547 /* FIXME: underflows must be unconditional, standard verdicts
548 < 0 (not ARPT_RETURN). --RR */
549
550 /* Clear counters and comefrom */
551 e->counters = ((struct xt_counters) { 0, 0 });
552 e->comefrom = 0;
553
554 (*i)++;
555 return 0;
556 }
557
558 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
559 {
560 struct arpt_entry_target *t;
561
562 if (i && (*i)-- == 0)
563 return 1;
564
565 t = arpt_get_target(e);
566 if (t->u.kernel.target->destroy)
567 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
568 module_put(t->u.kernel.target->me);
569 return 0;
570 }
571
572 /* Checks and translates the user-supplied table segment (held in
573 * newinfo).
574 */
575 static int translate_table(const char *name,
576 unsigned int valid_hooks,
577 struct xt_table_info *newinfo,
578 void *entry0,
579 unsigned int size,
580 unsigned int number,
581 const unsigned int *hook_entries,
582 const unsigned int *underflows)
583 {
584 unsigned int i;
585 int ret;
586
587 newinfo->size = size;
588 newinfo->number = number;
589
590 /* Init all hooks to impossible value. */
591 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
592 newinfo->hook_entry[i] = 0xFFFFFFFF;
593 newinfo->underflow[i] = 0xFFFFFFFF;
594 }
595
596 duprintf("translate_table: size %u\n", newinfo->size);
597 i = 0;
598
599 /* Walk through entries, checking offsets. */
600 ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
601 check_entry_size_and_hooks,
602 newinfo,
603 entry0,
604 entry0 + size,
605 hook_entries, underflows, &i);
606 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
607 if (ret != 0)
608 return ret;
609
610 if (i != number) {
611 duprintf("translate_table: %u not %u entries\n",
612 i, number);
613 return -EINVAL;
614 }
615
616 /* Check hooks all assigned */
617 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
618 /* Only hooks which are valid */
619 if (!(valid_hooks & (1 << i)))
620 continue;
621 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
622 duprintf("Invalid hook entry %u %u\n",
623 i, hook_entries[i]);
624 return -EINVAL;
625 }
626 if (newinfo->underflow[i] == 0xFFFFFFFF) {
627 duprintf("Invalid underflow %u %u\n",
628 i, underflows[i]);
629 return -EINVAL;
630 }
631 }
632
633 if (!mark_source_chains(newinfo, valid_hooks, entry0)) {
634 duprintf("Looping hook\n");
635 return -ELOOP;
636 }
637
638 /* Finally, each sanity check must pass */
639 i = 0;
640 ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
641 find_check_entry, name, size, &i);
642
643 if (ret != 0) {
644 ARPT_ENTRY_ITERATE(entry0, newinfo->size,
645 cleanup_entry, &i);
646 return ret;
647 }
648
649 /* And one copy for every other CPU */
650 for_each_possible_cpu(i) {
651 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
652 memcpy(newinfo->entries[i], entry0, newinfo->size);
653 }
654
655 return ret;
656 }
657
658 /* Gets counters. */
659 static inline int add_entry_to_counter(const struct arpt_entry *e,
660 struct xt_counters total[],
661 unsigned int *i)
662 {
663 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
664
665 (*i)++;
666 return 0;
667 }
668
669 static inline int set_entry_to_counter(const struct arpt_entry *e,
670 struct xt_counters total[],
671 unsigned int *i)
672 {
673 SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
674
675 (*i)++;
676 return 0;
677 }
678
679 static void get_counters(const struct xt_table_info *t,
680 struct xt_counters counters[])
681 {
682 unsigned int cpu;
683 unsigned int i;
684 unsigned int curcpu;
685
686 /* Instead of clearing (by a previous call to memset())
687 * the counters and using adds, we set the counters
688 * with data used by 'current' CPU
689 * We dont care about preemption here.
690 */
691 curcpu = raw_smp_processor_id();
692
693 i = 0;
694 ARPT_ENTRY_ITERATE(t->entries[curcpu],
695 t->size,
696 set_entry_to_counter,
697 counters,
698 &i);
699
700 for_each_possible_cpu(cpu) {
701 if (cpu == curcpu)
702 continue;
703 i = 0;
704 ARPT_ENTRY_ITERATE(t->entries[cpu],
705 t->size,
706 add_entry_to_counter,
707 counters,
708 &i);
709 }
710 }
711
712 static inline struct xt_counters *alloc_counters(struct arpt_table *table)
713 {
714 unsigned int countersize;
715 struct xt_counters *counters;
716 struct xt_table_info *private = table->private;
717
718 /* We need atomic snapshot of counters: rest doesn't change
719 * (other than comefrom, which userspace doesn't care
720 * about).
721 */
722 countersize = sizeof(struct xt_counters) * private->number;
723 counters = vmalloc_node(countersize, numa_node_id());
724
725 if (counters == NULL)
726 return ERR_PTR(-ENOMEM);
727
728 /* First, sum counters... */
729 write_lock_bh(&table->lock);
730 get_counters(private, counters);
731 write_unlock_bh(&table->lock);
732
733 return counters;
734 }
735
736 static int copy_entries_to_user(unsigned int total_size,
737 struct arpt_table *table,
738 void __user *userptr)
739 {
740 unsigned int off, num;
741 struct arpt_entry *e;
742 struct xt_counters *counters;
743 struct xt_table_info *private = table->private;
744 int ret = 0;
745 void *loc_cpu_entry;
746
747 counters = alloc_counters(table);
748 if (IS_ERR(counters))
749 return PTR_ERR(counters);
750
751 loc_cpu_entry = private->entries[raw_smp_processor_id()];
752 /* ... then copy entire thing ... */
753 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
754 ret = -EFAULT;
755 goto free_counters;
756 }
757
758 /* FIXME: use iterator macros --RR */
759 /* ... then go back and fix counters and names */
760 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
761 struct arpt_entry_target *t;
762
763 e = (struct arpt_entry *)(loc_cpu_entry + off);
764 if (copy_to_user(userptr + off
765 + offsetof(struct arpt_entry, counters),
766 &counters[num],
767 sizeof(counters[num])) != 0) {
768 ret = -EFAULT;
769 goto free_counters;
770 }
771
772 t = arpt_get_target(e);
773 if (copy_to_user(userptr + off + e->target_offset
774 + offsetof(struct arpt_entry_target,
775 u.user.name),
776 t->u.kernel.target->name,
777 strlen(t->u.kernel.target->name)+1) != 0) {
778 ret = -EFAULT;
779 goto free_counters;
780 }
781 }
782
783 free_counters:
784 vfree(counters);
785 return ret;
786 }
787
788 #ifdef CONFIG_COMPAT
789 static void compat_standard_from_user(void *dst, void *src)
790 {
791 int v = *(compat_int_t *)src;
792
793 if (v > 0)
794 v += xt_compat_calc_jump(NF_ARP, v);
795 memcpy(dst, &v, sizeof(v));
796 }
797
798 static int compat_standard_to_user(void __user *dst, void *src)
799 {
800 compat_int_t cv = *(int *)src;
801
802 if (cv > 0)
803 cv -= xt_compat_calc_jump(NF_ARP, cv);
804 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
805 }
806
807 static int compat_calc_entry(struct arpt_entry *e,
808 const struct xt_table_info *info,
809 void *base, struct xt_table_info *newinfo)
810 {
811 struct arpt_entry_target *t;
812 unsigned int entry_offset;
813 int off, i, ret;
814
815 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
816 entry_offset = (void *)e - base;
817
818 t = arpt_get_target(e);
819 off += xt_compat_target_offset(t->u.kernel.target);
820 newinfo->size -= off;
821 ret = xt_compat_add_offset(NF_ARP, entry_offset, off);
822 if (ret)
823 return ret;
824
825 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
826 if (info->hook_entry[i] &&
827 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
828 newinfo->hook_entry[i] -= off;
829 if (info->underflow[i] &&
830 (e < (struct arpt_entry *)(base + info->underflow[i])))
831 newinfo->underflow[i] -= off;
832 }
833 return 0;
834 }
835
836 static int compat_table_info(const struct xt_table_info *info,
837 struct xt_table_info *newinfo)
838 {
839 void *loc_cpu_entry;
840
841 if (!newinfo || !info)
842 return -EINVAL;
843
844 /* we dont care about newinfo->entries[] */
845 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
846 newinfo->initial_entries = 0;
847 loc_cpu_entry = info->entries[raw_smp_processor_id()];
848 return ARPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
849 compat_calc_entry, info, loc_cpu_entry,
850 newinfo);
851 }
852 #endif
853
854 static int get_info(struct net *net, void __user *user, int *len, int compat)
855 {
856 char name[ARPT_TABLE_MAXNAMELEN];
857 struct arpt_table *t;
858 int ret;
859
860 if (*len != sizeof(struct arpt_getinfo)) {
861 duprintf("length %u != %Zu\n", *len,
862 sizeof(struct arpt_getinfo));
863 return -EINVAL;
864 }
865
866 if (copy_from_user(name, user, sizeof(name)) != 0)
867 return -EFAULT;
868
869 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
870 #ifdef CONFIG_COMPAT
871 if (compat)
872 xt_compat_lock(NF_ARP);
873 #endif
874 t = try_then_request_module(xt_find_table_lock(net, NF_ARP, name),
875 "arptable_%s", name);
876 if (t && !IS_ERR(t)) {
877 struct arpt_getinfo info;
878 struct xt_table_info *private = t->private;
879
880 #ifdef CONFIG_COMPAT
881 if (compat) {
882 struct xt_table_info tmp;
883 ret = compat_table_info(private, &tmp);
884 xt_compat_flush_offsets(NF_ARP);
885 private = &tmp;
886 }
887 #endif
888 info.valid_hooks = t->valid_hooks;
889 memcpy(info.hook_entry, private->hook_entry,
890 sizeof(info.hook_entry));
891 memcpy(info.underflow, private->underflow,
892 sizeof(info.underflow));
893 info.num_entries = private->number;
894 info.size = private->size;
895 strcpy(info.name, name);
896
897 if (copy_to_user(user, &info, *len) != 0)
898 ret = -EFAULT;
899 else
900 ret = 0;
901 xt_table_unlock(t);
902 module_put(t->me);
903 } else
904 ret = t ? PTR_ERR(t) : -ENOENT;
905 #ifdef CONFIG_COMPAT
906 if (compat)
907 xt_compat_unlock(NF_ARP);
908 #endif
909 return ret;
910 }
911
912 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
913 int *len)
914 {
915 int ret;
916 struct arpt_get_entries get;
917 struct arpt_table *t;
918
919 if (*len < sizeof(get)) {
920 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
921 return -EINVAL;
922 }
923 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
924 return -EFAULT;
925 if (*len != sizeof(struct arpt_get_entries) + get.size) {
926 duprintf("get_entries: %u != %Zu\n", *len,
927 sizeof(struct arpt_get_entries) + get.size);
928 return -EINVAL;
929 }
930
931 t = xt_find_table_lock(net, NF_ARP, get.name);
932 if (t && !IS_ERR(t)) {
933 struct xt_table_info *private = t->private;
934 duprintf("t->private->number = %u\n",
935 private->number);
936 if (get.size == private->size)
937 ret = copy_entries_to_user(private->size,
938 t, uptr->entrytable);
939 else {
940 duprintf("get_entries: I've got %u not %u!\n",
941 private->size, get.size);
942 ret = -EINVAL;
943 }
944 module_put(t->me);
945 xt_table_unlock(t);
946 } else
947 ret = t ? PTR_ERR(t) : -ENOENT;
948
949 return ret;
950 }
951
952 static int __do_replace(struct net *net, const char *name,
953 unsigned int valid_hooks,
954 struct xt_table_info *newinfo,
955 unsigned int num_counters,
956 void __user *counters_ptr)
957 {
958 int ret;
959 struct arpt_table *t;
960 struct xt_table_info *oldinfo;
961 struct xt_counters *counters;
962 void *loc_cpu_old_entry;
963
964 ret = 0;
965 counters = vmalloc_node(num_counters * sizeof(struct xt_counters),
966 numa_node_id());
967 if (!counters) {
968 ret = -ENOMEM;
969 goto out;
970 }
971
972 t = try_then_request_module(xt_find_table_lock(net, NF_ARP, name),
973 "arptable_%s", name);
974 if (!t || IS_ERR(t)) {
975 ret = t ? PTR_ERR(t) : -ENOENT;
976 goto free_newinfo_counters_untrans;
977 }
978
979 /* You lied! */
980 if (valid_hooks != t->valid_hooks) {
981 duprintf("Valid hook crap: %08X vs %08X\n",
982 valid_hooks, t->valid_hooks);
983 ret = -EINVAL;
984 goto put_module;
985 }
986
987 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
988 if (!oldinfo)
989 goto put_module;
990
991 /* Update module usage count based on number of rules */
992 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
993 oldinfo->number, oldinfo->initial_entries, newinfo->number);
994 if ((oldinfo->number > oldinfo->initial_entries) ||
995 (newinfo->number <= oldinfo->initial_entries))
996 module_put(t->me);
997 if ((oldinfo->number > oldinfo->initial_entries) &&
998 (newinfo->number <= oldinfo->initial_entries))
999 module_put(t->me);
1000
1001 /* Get the old counters. */
1002 get_counters(oldinfo, counters);
1003 /* Decrease module usage counts and free resource */
1004 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1005 ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
1006 NULL);
1007
1008 xt_free_table_info(oldinfo);
1009 if (copy_to_user(counters_ptr, counters,
1010 sizeof(struct xt_counters) * num_counters) != 0)
1011 ret = -EFAULT;
1012 vfree(counters);
1013 xt_table_unlock(t);
1014 return ret;
1015
1016 put_module:
1017 module_put(t->me);
1018 xt_table_unlock(t);
1019 free_newinfo_counters_untrans:
1020 vfree(counters);
1021 out:
1022 return ret;
1023 }
1024
1025 static int do_replace(struct net *net, void __user *user, unsigned int len)
1026 {
1027 int ret;
1028 struct arpt_replace tmp;
1029 struct xt_table_info *newinfo;
1030 void *loc_cpu_entry;
1031
1032 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1033 return -EFAULT;
1034
1035 /* overflow check */
1036 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1037 return -ENOMEM;
1038
1039 newinfo = xt_alloc_table_info(tmp.size);
1040 if (!newinfo)
1041 return -ENOMEM;
1042
1043 /* choose the copy that is on our node/cpu */
1044 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1045 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1046 tmp.size) != 0) {
1047 ret = -EFAULT;
1048 goto free_newinfo;
1049 }
1050
1051 ret = translate_table(tmp.name, tmp.valid_hooks,
1052 newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1053 tmp.hook_entry, tmp.underflow);
1054 if (ret != 0)
1055 goto free_newinfo;
1056
1057 duprintf("arp_tables: Translated table\n");
1058
1059 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1060 tmp.num_counters, tmp.counters);
1061 if (ret)
1062 goto free_newinfo_untrans;
1063 return 0;
1064
1065 free_newinfo_untrans:
1066 ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1067 free_newinfo:
1068 xt_free_table_info(newinfo);
1069 return ret;
1070 }
1071
1072 /* We're lazy, and add to the first CPU; overflow works its fey magic
1073 * and everything is OK.
1074 */
1075 static inline int add_counter_to_entry(struct arpt_entry *e,
1076 const struct xt_counters addme[],
1077 unsigned int *i)
1078 {
1079
1080 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1081
1082 (*i)++;
1083 return 0;
1084 }
1085
1086 static int do_add_counters(struct net *net, void __user *user, unsigned int len,
1087 int compat)
1088 {
1089 unsigned int i;
1090 struct xt_counters_info tmp;
1091 struct xt_counters *paddc;
1092 unsigned int num_counters;
1093 char *name;
1094 int size;
1095 void *ptmp;
1096 struct arpt_table *t;
1097 struct xt_table_info *private;
1098 int ret = 0;
1099 void *loc_cpu_entry;
1100 #ifdef CONFIG_COMPAT
1101 struct compat_xt_counters_info compat_tmp;
1102
1103 if (compat) {
1104 ptmp = &compat_tmp;
1105 size = sizeof(struct compat_xt_counters_info);
1106 } else
1107 #endif
1108 {
1109 ptmp = &tmp;
1110 size = sizeof(struct xt_counters_info);
1111 }
1112
1113 if (copy_from_user(ptmp, user, size) != 0)
1114 return -EFAULT;
1115
1116 #ifdef CONFIG_COMPAT
1117 if (compat) {
1118 num_counters = compat_tmp.num_counters;
1119 name = compat_tmp.name;
1120 } else
1121 #endif
1122 {
1123 num_counters = tmp.num_counters;
1124 name = tmp.name;
1125 }
1126
1127 if (len != size + num_counters * sizeof(struct xt_counters))
1128 return -EINVAL;
1129
1130 paddc = vmalloc_node(len - size, numa_node_id());
1131 if (!paddc)
1132 return -ENOMEM;
1133
1134 if (copy_from_user(paddc, user + size, len - size) != 0) {
1135 ret = -EFAULT;
1136 goto free;
1137 }
1138
1139 t = xt_find_table_lock(net, NF_ARP, name);
1140 if (!t || IS_ERR(t)) {
1141 ret = t ? PTR_ERR(t) : -ENOENT;
1142 goto free;
1143 }
1144
1145 write_lock_bh(&t->lock);
1146 private = t->private;
1147 if (private->number != num_counters) {
1148 ret = -EINVAL;
1149 goto unlock_up_free;
1150 }
1151
1152 i = 0;
1153 /* Choose the copy that is on our node */
1154 loc_cpu_entry = private->entries[smp_processor_id()];
1155 ARPT_ENTRY_ITERATE(loc_cpu_entry,
1156 private->size,
1157 add_counter_to_entry,
1158 paddc,
1159 &i);
1160 unlock_up_free:
1161 write_unlock_bh(&t->lock);
1162 xt_table_unlock(t);
1163 module_put(t->me);
1164 free:
1165 vfree(paddc);
1166
1167 return ret;
1168 }
1169
1170 #ifdef CONFIG_COMPAT
1171 static inline int
1172 compat_release_entry(struct compat_arpt_entry *e, unsigned int *i)
1173 {
1174 struct arpt_entry_target *t;
1175
1176 if (i && (*i)-- == 0)
1177 return 1;
1178
1179 t = compat_arpt_get_target(e);
1180 module_put(t->u.kernel.target->me);
1181 return 0;
1182 }
1183
1184 static inline int
1185 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1186 struct xt_table_info *newinfo,
1187 unsigned int *size,
1188 unsigned char *base,
1189 unsigned char *limit,
1190 unsigned int *hook_entries,
1191 unsigned int *underflows,
1192 unsigned int *i,
1193 const char *name)
1194 {
1195 struct arpt_entry_target *t;
1196 struct xt_target *target;
1197 unsigned int entry_offset;
1198 int ret, off, h;
1199
1200 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1201 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0
1202 || (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1203 duprintf("Bad offset %p, limit = %p\n", e, limit);
1204 return -EINVAL;
1205 }
1206
1207 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1208 sizeof(struct compat_xt_entry_target)) {
1209 duprintf("checking: element %p size %u\n",
1210 e, e->next_offset);
1211 return -EINVAL;
1212 }
1213
1214 /* For purposes of check_entry casting the compat entry is fine */
1215 ret = check_entry((struct arpt_entry *)e, name);
1216 if (ret)
1217 return ret;
1218
1219 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1220 entry_offset = (void *)e - (void *)base;
1221
1222 t = compat_arpt_get_target(e);
1223 target = try_then_request_module(xt_find_target(NF_ARP,
1224 t->u.user.name,
1225 t->u.user.revision),
1226 "arpt_%s", t->u.user.name);
1227 if (IS_ERR(target) || !target) {
1228 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1229 t->u.user.name);
1230 ret = target ? PTR_ERR(target) : -ENOENT;
1231 goto out;
1232 }
1233 t->u.kernel.target = target;
1234
1235 off += xt_compat_target_offset(target);
1236 *size += off;
1237 ret = xt_compat_add_offset(NF_ARP, entry_offset, off);
1238 if (ret)
1239 goto release_target;
1240
1241 /* Check hooks & underflows */
1242 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1243 if ((unsigned char *)e - base == hook_entries[h])
1244 newinfo->hook_entry[h] = hook_entries[h];
1245 if ((unsigned char *)e - base == underflows[h])
1246 newinfo->underflow[h] = underflows[h];
1247 }
1248
1249 /* Clear counters and comefrom */
1250 memset(&e->counters, 0, sizeof(e->counters));
1251 e->comefrom = 0;
1252
1253 (*i)++;
1254 return 0;
1255
1256 release_target:
1257 module_put(t->u.kernel.target->me);
1258 out:
1259 return ret;
1260 }
1261
1262 static int
1263 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1264 unsigned int *size, const char *name,
1265 struct xt_table_info *newinfo, unsigned char *base)
1266 {
1267 struct arpt_entry_target *t;
1268 struct xt_target *target;
1269 struct arpt_entry *de;
1270 unsigned int origsize;
1271 int ret, h;
1272
1273 ret = 0;
1274 origsize = *size;
1275 de = (struct arpt_entry *)*dstptr;
1276 memcpy(de, e, sizeof(struct arpt_entry));
1277 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1278
1279 *dstptr += sizeof(struct arpt_entry);
1280 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1281
1282 de->target_offset = e->target_offset - (origsize - *size);
1283 t = compat_arpt_get_target(e);
1284 target = t->u.kernel.target;
1285 xt_compat_target_from_user(t, dstptr, size);
1286
1287 de->next_offset = e->next_offset - (origsize - *size);
1288 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1289 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1290 newinfo->hook_entry[h] -= origsize - *size;
1291 if ((unsigned char *)de - base < newinfo->underflow[h])
1292 newinfo->underflow[h] -= origsize - *size;
1293 }
1294 return ret;
1295 }
1296
1297 static inline int compat_check_entry(struct arpt_entry *e, const char *name,
1298 unsigned int *i)
1299 {
1300 int ret;
1301
1302 ret = check_target(e, name);
1303 if (ret)
1304 return ret;
1305
1306 (*i)++;
1307 return 0;
1308 }
1309
1310 static int translate_compat_table(const char *name,
1311 unsigned int valid_hooks,
1312 struct xt_table_info **pinfo,
1313 void **pentry0,
1314 unsigned int total_size,
1315 unsigned int number,
1316 unsigned int *hook_entries,
1317 unsigned int *underflows)
1318 {
1319 unsigned int i, j;
1320 struct xt_table_info *newinfo, *info;
1321 void *pos, *entry0, *entry1;
1322 unsigned int size;
1323 int ret;
1324
1325 info = *pinfo;
1326 entry0 = *pentry0;
1327 size = total_size;
1328 info->number = number;
1329
1330 /* Init all hooks to impossible value. */
1331 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1332 info->hook_entry[i] = 0xFFFFFFFF;
1333 info->underflow[i] = 0xFFFFFFFF;
1334 }
1335
1336 duprintf("translate_compat_table: size %u\n", info->size);
1337 j = 0;
1338 xt_compat_lock(NF_ARP);
1339 /* Walk through entries, checking offsets. */
1340 ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
1341 check_compat_entry_size_and_hooks,
1342 info, &size, entry0,
1343 entry0 + total_size,
1344 hook_entries, underflows, &j, name);
1345 if (ret != 0)
1346 goto out_unlock;
1347
1348 ret = -EINVAL;
1349 if (j != number) {
1350 duprintf("translate_compat_table: %u not %u entries\n",
1351 j, number);
1352 goto out_unlock;
1353 }
1354
1355 /* Check hooks all assigned */
1356 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1357 /* Only hooks which are valid */
1358 if (!(valid_hooks & (1 << i)))
1359 continue;
1360 if (info->hook_entry[i] == 0xFFFFFFFF) {
1361 duprintf("Invalid hook entry %u %u\n",
1362 i, hook_entries[i]);
1363 goto out_unlock;
1364 }
1365 if (info->underflow[i] == 0xFFFFFFFF) {
1366 duprintf("Invalid underflow %u %u\n",
1367 i, underflows[i]);
1368 goto out_unlock;
1369 }
1370 }
1371
1372 ret = -ENOMEM;
1373 newinfo = xt_alloc_table_info(size);
1374 if (!newinfo)
1375 goto out_unlock;
1376
1377 newinfo->number = number;
1378 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1379 newinfo->hook_entry[i] = info->hook_entry[i];
1380 newinfo->underflow[i] = info->underflow[i];
1381 }
1382 entry1 = newinfo->entries[raw_smp_processor_id()];
1383 pos = entry1;
1384 size = total_size;
1385 ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
1386 compat_copy_entry_from_user,
1387 &pos, &size, name, newinfo, entry1);
1388 xt_compat_flush_offsets(NF_ARP);
1389 xt_compat_unlock(NF_ARP);
1390 if (ret)
1391 goto free_newinfo;
1392
1393 ret = -ELOOP;
1394 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1395 goto free_newinfo;
1396
1397 i = 0;
1398 ret = ARPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1399 name, &i);
1400 if (ret) {
1401 j -= i;
1402 COMPAT_ARPT_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
1403 compat_release_entry, &j);
1404 ARPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1405 xt_free_table_info(newinfo);
1406 return ret;
1407 }
1408
1409 /* And one copy for every other CPU */
1410 for_each_possible_cpu(i)
1411 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1412 memcpy(newinfo->entries[i], entry1, newinfo->size);
1413
1414 *pinfo = newinfo;
1415 *pentry0 = entry1;
1416 xt_free_table_info(info);
1417 return 0;
1418
1419 free_newinfo:
1420 xt_free_table_info(newinfo);
1421 out:
1422 COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1423 return ret;
1424 out_unlock:
1425 xt_compat_flush_offsets(NF_ARP);
1426 xt_compat_unlock(NF_ARP);
1427 goto out;
1428 }
1429
1430 struct compat_arpt_replace {
1431 char name[ARPT_TABLE_MAXNAMELEN];
1432 u32 valid_hooks;
1433 u32 num_entries;
1434 u32 size;
1435 u32 hook_entry[NF_ARP_NUMHOOKS];
1436 u32 underflow[NF_ARP_NUMHOOKS];
1437 u32 num_counters;
1438 compat_uptr_t counters;
1439 struct compat_arpt_entry entries[0];
1440 };
1441
1442 static int compat_do_replace(struct net *net, void __user *user,
1443 unsigned int len)
1444 {
1445 int ret;
1446 struct compat_arpt_replace tmp;
1447 struct xt_table_info *newinfo;
1448 void *loc_cpu_entry;
1449
1450 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1451 return -EFAULT;
1452
1453 /* overflow check */
1454 if (tmp.size >= INT_MAX / num_possible_cpus())
1455 return -ENOMEM;
1456 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1457 return -ENOMEM;
1458
1459 newinfo = xt_alloc_table_info(tmp.size);
1460 if (!newinfo)
1461 return -ENOMEM;
1462
1463 /* choose the copy that is on our node/cpu */
1464 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1465 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1466 ret = -EFAULT;
1467 goto free_newinfo;
1468 }
1469
1470 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1471 &newinfo, &loc_cpu_entry, tmp.size,
1472 tmp.num_entries, tmp.hook_entry,
1473 tmp.underflow);
1474 if (ret != 0)
1475 goto free_newinfo;
1476
1477 duprintf("compat_do_replace: Translated table\n");
1478
1479 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1480 tmp.num_counters, compat_ptr(tmp.counters));
1481 if (ret)
1482 goto free_newinfo_untrans;
1483 return 0;
1484
1485 free_newinfo_untrans:
1486 ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1487 free_newinfo:
1488 xt_free_table_info(newinfo);
1489 return ret;
1490 }
1491
1492 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1493 unsigned int len)
1494 {
1495 int ret;
1496
1497 if (!capable(CAP_NET_ADMIN))
1498 return -EPERM;
1499
1500 switch (cmd) {
1501 case ARPT_SO_SET_REPLACE:
1502 ret = compat_do_replace(sk->sk_net, user, len);
1503 break;
1504
1505 case ARPT_SO_SET_ADD_COUNTERS:
1506 ret = do_add_counters(sk->sk_net, user, len, 1);
1507 break;
1508
1509 default:
1510 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1511 ret = -EINVAL;
1512 }
1513
1514 return ret;
1515 }
1516
1517 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1518 compat_uint_t *size,
1519 struct xt_counters *counters,
1520 unsigned int *i)
1521 {
1522 struct arpt_entry_target *t;
1523 struct compat_arpt_entry __user *ce;
1524 u_int16_t target_offset, next_offset;
1525 compat_uint_t origsize;
1526 int ret;
1527
1528 ret = -EFAULT;
1529 origsize = *size;
1530 ce = (struct compat_arpt_entry __user *)*dstptr;
1531 if (copy_to_user(ce, e, sizeof(struct arpt_entry)))
1532 goto out;
1533
1534 if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
1535 goto out;
1536
1537 *dstptr += sizeof(struct compat_arpt_entry);
1538 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1539
1540 target_offset = e->target_offset - (origsize - *size);
1541
1542 t = arpt_get_target(e);
1543 ret = xt_compat_target_to_user(t, dstptr, size);
1544 if (ret)
1545 goto out;
1546 ret = -EFAULT;
1547 next_offset = e->next_offset - (origsize - *size);
1548 if (put_user(target_offset, &ce->target_offset))
1549 goto out;
1550 if (put_user(next_offset, &ce->next_offset))
1551 goto out;
1552
1553 (*i)++;
1554 return 0;
1555 out:
1556 return ret;
1557 }
1558
1559 static int compat_copy_entries_to_user(unsigned int total_size,
1560 struct arpt_table *table,
1561 void __user *userptr)
1562 {
1563 struct xt_counters *counters;
1564 struct xt_table_info *private = table->private;
1565 void __user *pos;
1566 unsigned int size;
1567 int ret = 0;
1568 void *loc_cpu_entry;
1569 unsigned int i = 0;
1570
1571 counters = alloc_counters(table);
1572 if (IS_ERR(counters))
1573 return PTR_ERR(counters);
1574
1575 /* choose the copy on our node/cpu */
1576 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1577 pos = userptr;
1578 size = total_size;
1579 ret = ARPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1580 compat_copy_entry_to_user,
1581 &pos, &size, counters, &i);
1582 vfree(counters);
1583 return ret;
1584 }
1585
1586 struct compat_arpt_get_entries {
1587 char name[ARPT_TABLE_MAXNAMELEN];
1588 compat_uint_t size;
1589 struct compat_arpt_entry entrytable[0];
1590 };
1591
1592 static int compat_get_entries(struct net *net,
1593 struct compat_arpt_get_entries __user *uptr,
1594 int *len)
1595 {
1596 int ret;
1597 struct compat_arpt_get_entries get;
1598 struct arpt_table *t;
1599
1600 if (*len < sizeof(get)) {
1601 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1602 return -EINVAL;
1603 }
1604 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1605 return -EFAULT;
1606 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1607 duprintf("compat_get_entries: %u != %zu\n",
1608 *len, sizeof(get) + get.size);
1609 return -EINVAL;
1610 }
1611
1612 xt_compat_lock(NF_ARP);
1613 t = xt_find_table_lock(net, NF_ARP, get.name);
1614 if (t && !IS_ERR(t)) {
1615 struct xt_table_info *private = t->private;
1616 struct xt_table_info info;
1617
1618 duprintf("t->private->number = %u\n", private->number);
1619 ret = compat_table_info(private, &info);
1620 if (!ret && get.size == info.size) {
1621 ret = compat_copy_entries_to_user(private->size,
1622 t, uptr->entrytable);
1623 } else if (!ret) {
1624 duprintf("compat_get_entries: I've got %u not %u!\n",
1625 private->size, get.size);
1626 ret = -EINVAL;
1627 }
1628 xt_compat_flush_offsets(NF_ARP);
1629 module_put(t->me);
1630 xt_table_unlock(t);
1631 } else
1632 ret = t ? PTR_ERR(t) : -ENOENT;
1633
1634 xt_compat_unlock(NF_ARP);
1635 return ret;
1636 }
1637
1638 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1639
1640 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1641 int *len)
1642 {
1643 int ret;
1644
1645 if (!capable(CAP_NET_ADMIN))
1646 return -EPERM;
1647
1648 switch (cmd) {
1649 case ARPT_SO_GET_INFO:
1650 ret = get_info(sk->sk_net, user, len, 1);
1651 break;
1652 case ARPT_SO_GET_ENTRIES:
1653 ret = compat_get_entries(sk->sk_net, user, len);
1654 break;
1655 default:
1656 ret = do_arpt_get_ctl(sk, cmd, user, len);
1657 }
1658 return ret;
1659 }
1660 #endif
1661
1662 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1663 {
1664 int ret;
1665
1666 if (!capable(CAP_NET_ADMIN))
1667 return -EPERM;
1668
1669 switch (cmd) {
1670 case ARPT_SO_SET_REPLACE:
1671 ret = do_replace(sk->sk_net, user, len);
1672 break;
1673
1674 case ARPT_SO_SET_ADD_COUNTERS:
1675 ret = do_add_counters(sk->sk_net, user, len, 0);
1676 break;
1677
1678 default:
1679 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1680 ret = -EINVAL;
1681 }
1682
1683 return ret;
1684 }
1685
1686 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1687 {
1688 int ret;
1689
1690 if (!capable(CAP_NET_ADMIN))
1691 return -EPERM;
1692
1693 switch (cmd) {
1694 case ARPT_SO_GET_INFO:
1695 ret = get_info(sk->sk_net, user, len, 0);
1696 break;
1697
1698 case ARPT_SO_GET_ENTRIES:
1699 ret = get_entries(sk->sk_net, user, len);
1700 break;
1701
1702 case ARPT_SO_GET_REVISION_TARGET: {
1703 struct xt_get_revision rev;
1704
1705 if (*len != sizeof(rev)) {
1706 ret = -EINVAL;
1707 break;
1708 }
1709 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1710 ret = -EFAULT;
1711 break;
1712 }
1713
1714 try_then_request_module(xt_find_revision(NF_ARP, rev.name,
1715 rev.revision, 1, &ret),
1716 "arpt_%s", rev.name);
1717 break;
1718 }
1719
1720 default:
1721 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1722 ret = -EINVAL;
1723 }
1724
1725 return ret;
1726 }
1727
1728 struct arpt_table *arpt_register_table(struct net *net,
1729 struct arpt_table *table,
1730 const struct arpt_replace *repl)
1731 {
1732 int ret;
1733 struct xt_table_info *newinfo;
1734 struct xt_table_info bootstrap
1735 = { 0, 0, 0, { 0 }, { 0 }, { } };
1736 void *loc_cpu_entry;
1737 struct xt_table *new_table;
1738
1739 newinfo = xt_alloc_table_info(repl->size);
1740 if (!newinfo) {
1741 ret = -ENOMEM;
1742 goto out;
1743 }
1744
1745 /* choose the copy on our node/cpu */
1746 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1747 memcpy(loc_cpu_entry, repl->entries, repl->size);
1748
1749 ret = translate_table(table->name, table->valid_hooks,
1750 newinfo, loc_cpu_entry, repl->size,
1751 repl->num_entries,
1752 repl->hook_entry,
1753 repl->underflow);
1754
1755 duprintf("arpt_register_table: translate table gives %d\n", ret);
1756 if (ret != 0)
1757 goto out_free;
1758
1759 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1760 if (IS_ERR(new_table)) {
1761 ret = PTR_ERR(new_table);
1762 goto out_free;
1763 }
1764 return new_table;
1765
1766 out_free:
1767 xt_free_table_info(newinfo);
1768 out:
1769 return ERR_PTR(ret);
1770 }
1771
1772 void arpt_unregister_table(struct arpt_table *table)
1773 {
1774 struct xt_table_info *private;
1775 void *loc_cpu_entry;
1776 struct module *table_owner = table->me;
1777
1778 private = xt_unregister_table(table);
1779
1780 /* Decrease module usage counts and free resources */
1781 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1782 ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
1783 cleanup_entry, NULL);
1784 if (private->number > private->initial_entries)
1785 module_put(table_owner);
1786 xt_free_table_info(private);
1787 }
1788
1789 /* The built-in targets: standard (NULL) and error. */
1790 static struct arpt_target arpt_standard_target __read_mostly = {
1791 .name = ARPT_STANDARD_TARGET,
1792 .targetsize = sizeof(int),
1793 .family = NF_ARP,
1794 #ifdef CONFIG_COMPAT
1795 .compatsize = sizeof(compat_int_t),
1796 .compat_from_user = compat_standard_from_user,
1797 .compat_to_user = compat_standard_to_user,
1798 #endif
1799 };
1800
1801 static struct arpt_target arpt_error_target __read_mostly = {
1802 .name = ARPT_ERROR_TARGET,
1803 .target = arpt_error,
1804 .targetsize = ARPT_FUNCTION_MAXNAMELEN,
1805 .family = NF_ARP,
1806 };
1807
1808 static struct nf_sockopt_ops arpt_sockopts = {
1809 .pf = PF_INET,
1810 .set_optmin = ARPT_BASE_CTL,
1811 .set_optmax = ARPT_SO_SET_MAX+1,
1812 .set = do_arpt_set_ctl,
1813 #ifdef CONFIG_COMPAT
1814 .compat_set = compat_do_arpt_set_ctl,
1815 #endif
1816 .get_optmin = ARPT_BASE_CTL,
1817 .get_optmax = ARPT_SO_GET_MAX+1,
1818 .get = do_arpt_get_ctl,
1819 #ifdef CONFIG_COMPAT
1820 .compat_get = compat_do_arpt_get_ctl,
1821 #endif
1822 .owner = THIS_MODULE,
1823 };
1824
1825 static int __net_init arp_tables_net_init(struct net *net)
1826 {
1827 return xt_proto_init(net, NF_ARP);
1828 }
1829
1830 static void __net_exit arp_tables_net_exit(struct net *net)
1831 {
1832 xt_proto_fini(net, NF_ARP);
1833 }
1834
1835 static struct pernet_operations arp_tables_net_ops = {
1836 .init = arp_tables_net_init,
1837 .exit = arp_tables_net_exit,
1838 };
1839
1840 static int __init arp_tables_init(void)
1841 {
1842 int ret;
1843
1844 ret = register_pernet_subsys(&arp_tables_net_ops);
1845 if (ret < 0)
1846 goto err1;
1847
1848 /* Noone else will be downing sem now, so we won't sleep */
1849 ret = xt_register_target(&arpt_standard_target);
1850 if (ret < 0)
1851 goto err2;
1852 ret = xt_register_target(&arpt_error_target);
1853 if (ret < 0)
1854 goto err3;
1855
1856 /* Register setsockopt */
1857 ret = nf_register_sockopt(&arpt_sockopts);
1858 if (ret < 0)
1859 goto err4;
1860
1861 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1862 return 0;
1863
1864 err4:
1865 xt_unregister_target(&arpt_error_target);
1866 err3:
1867 xt_unregister_target(&arpt_standard_target);
1868 err2:
1869 unregister_pernet_subsys(&arp_tables_net_ops);
1870 err1:
1871 return ret;
1872 }
1873
1874 static void __exit arp_tables_fini(void)
1875 {
1876 nf_unregister_sockopt(&arpt_sockopts);
1877 xt_unregister_target(&arpt_error_target);
1878 xt_unregister_target(&arpt_standard_target);
1879 unregister_pernet_subsys(&arp_tables_net_ops);
1880 }
1881
1882 EXPORT_SYMBOL(arpt_register_table);
1883 EXPORT_SYMBOL(arpt_unregister_table);
1884 EXPORT_SYMBOL(arpt_do_table);
1885
1886 module_init(arp_tables_init);
1887 module_exit(arp_tables_fini);
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