1/* 2 * Packet matching code for ARP packets. 3 * 4 * Based heavily, if not almost entirely, upon ip_tables.c framework. 5 * 6 * Some ARP specific bits are: 7 * 8 * Copyright (C) 2002 David S. Miller (davem@redhat.com) 9 * 10 */ 11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12#include <linux/kernel.h> 13#include <linux/skbuff.h> 14#include <linux/netdevice.h> 15#include <linux/capability.h> 16#include <linux/if_arp.h> 17#include <linux/kmod.h> 18#include <linux/vmalloc.h> 19#include <linux/proc_fs.h> 20#include <linux/module.h> 21#include <linux/init.h> 22#include <linux/mutex.h> 23#include <linux/err.h> 24#include <net/compat.h> 25#include <net/sock.h> 26#include <asm/uaccess.h> 27 28#include <linux/netfilter/x_tables.h> 29#include <linux/netfilter_arp/arp_tables.h> 30#include "../../netfilter/xt_repldata.h" 31 32MODULE_LICENSE("GPL"); 33MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); 34MODULE_DESCRIPTION("arptables core"); 35 36/*#define DEBUG_ARP_TABLES*/ 37/*#define DEBUG_ARP_TABLES_USER*/ 38 39#ifdef DEBUG_ARP_TABLES 40#define dprintf(format, args...) printk(format , ## args) 41#else 42#define dprintf(format, args...) 43#endif 44 45#ifdef DEBUG_ARP_TABLES_USER 46#define duprintf(format, args...) printk(format , ## args) 47#else 48#define duprintf(format, args...) 49#endif 50 51#ifdef CONFIG_NETFILTER_DEBUG 52#define ARP_NF_ASSERT(x) WARN_ON(!(x)) 53#else 54#define ARP_NF_ASSERT(x) 55#endif 56 57void *arpt_alloc_initial_table(const struct xt_table *info) 58{ 59 return xt_alloc_initial_table(arpt, ARPT); 60} 61EXPORT_SYMBOL_GPL(arpt_alloc_initial_table); 62 63static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap, 64 const char *hdr_addr, int len) 65{ 66 int i, ret; 67 68 if (len > ARPT_DEV_ADDR_LEN_MAX) 69 len = ARPT_DEV_ADDR_LEN_MAX; 70 71 ret = 0; 72 for (i = 0; i < len; i++) 73 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i]; 74 75 return (ret != 0); 76} 77 78/* 79 * Unfortunatly, _b and _mask are not aligned to an int (or long int) 80 * Some arches dont care, unrolling the loop is a win on them. 81 * For other arches, we only have a 16bit alignement. 82 */ 83static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask) 84{ 85#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 86 unsigned long ret = ifname_compare_aligned(_a, _b, _mask); 87#else 88 unsigned long ret = 0; 89 const u16 *a = (const u16 *)_a; 90 const u16 *b = (const u16 *)_b; 91 const u16 *mask = (const u16 *)_mask; 92 int i; 93 94 for (i = 0; i < IFNAMSIZ/sizeof(u16); i++) 95 ret |= (a[i] ^ b[i]) & mask[i]; 96#endif 97 return ret; 98} 99 100/* Returns whether packet matches rule or not. */ 101static inline int arp_packet_match(const struct arphdr *arphdr, 102 struct net_device *dev, 103 const char *indev, 104 const char *outdev, 105 const struct arpt_arp *arpinfo) 106{ 107 const char *arpptr = (char *)(arphdr + 1); 108 const char *src_devaddr, *tgt_devaddr; 109 __be32 src_ipaddr, tgt_ipaddr; 110 long ret; 111 112#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg))) 113 114 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop, 115 ARPT_INV_ARPOP)) { 116 dprintf("ARP operation field mismatch.\n"); 117 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n", 118 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask); 119 return 0; 120 } 121 122 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd, 123 ARPT_INV_ARPHRD)) { 124 dprintf("ARP hardware address format mismatch.\n"); 125 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n", 126 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask); 127 return 0; 128 } 129 130 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro, 131 ARPT_INV_ARPPRO)) { 132 dprintf("ARP protocol address format mismatch.\n"); 133 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n", 134 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask); 135 return 0; 136 } 137 138 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln, 139 ARPT_INV_ARPHLN)) { 140 dprintf("ARP hardware address length mismatch.\n"); 141 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n", 142 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask); 143 return 0; 144 } 145 146 src_devaddr = arpptr; 147 arpptr += dev->addr_len; 148 memcpy(&src_ipaddr, arpptr, sizeof(u32)); 149 arpptr += sizeof(u32); 150 tgt_devaddr = arpptr; 151 arpptr += dev->addr_len; 152 memcpy(&tgt_ipaddr, arpptr, sizeof(u32)); 153 154 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len), 155 ARPT_INV_SRCDEVADDR) || 156 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len), 157 ARPT_INV_TGTDEVADDR)) { 158 dprintf("Source or target device address mismatch.\n"); 159 160 return 0; 161 } 162 163 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr, 164 ARPT_INV_SRCIP) || 165 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr), 166 ARPT_INV_TGTIP)) { 167 dprintf("Source or target IP address mismatch.\n"); 168 169 dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n", 170 &src_ipaddr, 171 &arpinfo->smsk.s_addr, 172 &arpinfo->src.s_addr, 173 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : ""); 174 dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n", 175 &tgt_ipaddr, 176 &arpinfo->tmsk.s_addr, 177 &arpinfo->tgt.s_addr, 178 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : ""); 179 return 0; 180 } 181 182 /* Look for ifname matches. */ 183 ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask); 184 185 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) { 186 dprintf("VIA in mismatch (%s vs %s).%s\n", 187 indev, arpinfo->iniface, 188 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":""); 189 return 0; 190 } 191 192 ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask); 193 194 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) { 195 dprintf("VIA out mismatch (%s vs %s).%s\n", 196 outdev, arpinfo->outiface, 197 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":""); 198 return 0; 199 } 200 201 return 1; 202#undef FWINV 203} 204 205static inline int arp_checkentry(const struct arpt_arp *arp) 206{ 207 if (arp->flags & ~ARPT_F_MASK) { 208 duprintf("Unknown flag bits set: %08X\n", 209 arp->flags & ~ARPT_F_MASK); 210 return 0; 211 } 212 if (arp->invflags & ~ARPT_INV_MASK) { 213 duprintf("Unknown invflag bits set: %08X\n", 214 arp->invflags & ~ARPT_INV_MASK); 215 return 0; 216 } 217 218 return 1; 219} 220 221static unsigned int 222arpt_error(struct sk_buff *skb, const struct xt_action_param *par) 223{ 224 if (net_ratelimit()) 225 pr_err("arp_tables: error: '%s'\n", 226 (const char *)par->targinfo); 227 228 return NF_DROP; 229} 230 231static inline const struct arpt_entry_target * 232arpt_get_target_c(const struct arpt_entry *e) 233{ 234 return arpt_get_target((struct arpt_entry *)e); 235} 236 237static inline struct arpt_entry * 238get_entry(const void *base, unsigned int offset) 239{ 240 return (struct arpt_entry *)(base + offset); 241} 242 243static inline __pure 244struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry) 245{ 246 return (void *)entry + entry->next_offset; 247} 248 249unsigned 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; 263 264 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 265 return NF_DROP; 266 267 indev = in ? in->name : nulldevname; 268 outdev = out ? out->name : nulldevname; 269 270 xt_info_rdlock_bh(); 271 private = table->private; 272 table_base = private->entries[smp_processor_id()]; 273 274 e = get_entry(table_base, private->hook_entry[hook]); 275 back = get_entry(table_base, private->underflow[hook]); 276 277 acpar.in = in; 278 acpar.out = out; 279 acpar.hooknum = hook; 280 acpar.family = NFPROTO_ARP; 281 acpar.hotdrop = false; 282 283 arp = arp_hdr(skb); 284 do { 285 const struct arpt_entry_target *t; 286 287 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) { 288 e = arpt_next_entry(e); 289 continue; 290 } 291 292 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1); 293 294 t = arpt_get_target_c(e); 295 296 /* Standard target? */ 297 if (!t->u.kernel.target->target) { 298 int v; 299 300 v = ((struct arpt_standard_target *)t)->verdict; 301 if (v < 0) { 302 /* Pop from stack? */ 303 if (v != ARPT_RETURN) { 304 verdict = (unsigned)(-v) - 1; 305 break; 306 } 307 e = back; 308 back = get_entry(table_base, back->comefrom); 309 continue; 310 } 311 if (table_base + v 312 != arpt_next_entry(e)) { 313 /* Save old back ptr in next entry */ 314 struct arpt_entry *next = arpt_next_entry(e); 315 next->comefrom = (void *)back - table_base; 316 317 /* set back pointer to next entry */ 318 back = next; 319 } 320 321 e = get_entry(table_base, v); 322 continue; 323 } 324 325 /* Targets which reenter must return 326 * abs. verdicts 327 */ 328 acpar.target = t->u.kernel.target; 329 acpar.targinfo = t->data; 330 verdict = t->u.kernel.target->target(skb, &acpar); 331 332 /* Target might have changed stuff. */ 333 arp = arp_hdr(skb); 334 335 if (verdict == ARPT_CONTINUE) 336 e = arpt_next_entry(e); 337 else 338 /* Verdict */ 339 break; 340 } while (!acpar.hotdrop); 341 xt_info_rdunlock_bh(); 342 343 if (acpar.hotdrop) 344 return NF_DROP; 345 else 346 return verdict; 347} 348 349/* All zeroes == unconditional rule. */ 350static inline bool unconditional(const struct arpt_arp *arp) 351{ 352 static const struct arpt_arp uncond; 353 354 return memcmp(arp, &uncond, sizeof(uncond)) == 0; 355} 356 357/* Figures out from what hook each rule can be called: returns 0 if 358 * there are loops. Puts hook bitmask in comefrom. 359 */ 360static int mark_source_chains(const struct xt_table_info *newinfo, 361 unsigned int valid_hooks, void *entry0) 362{ 363 unsigned int hook; 364 365 /* No recursion; use packet counter to save back ptrs (reset 366 * to 0 as we leave), and comefrom to save source hook bitmask. 367 */ 368 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) { 369 unsigned int pos = newinfo->hook_entry[hook]; 370 struct arpt_entry *e 371 = (struct arpt_entry *)(entry0 + pos); 372 373 if (!(valid_hooks & (1 << hook))) 374 continue; 375 376 /* Set initial back pointer. */ 377 e->counters.pcnt = pos; 378 379 for (;;) { 380 const struct arpt_standard_target *t 381 = (void *)arpt_get_target_c(e); 382 int visited = e->comefrom & (1 << hook); 383 384 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) { 385 pr_notice("arptables: loop hook %u pos %u %08X.\n", 386 hook, pos, e->comefrom); 387 return 0; 388 } 389 e->comefrom 390 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS)); 391 392 /* Unconditional return/END. */ 393 if ((e->target_offset == sizeof(struct arpt_entry) && 394 (strcmp(t->target.u.user.name, 395 ARPT_STANDARD_TARGET) == 0) && 396 t->verdict < 0 && unconditional(&e->arp)) || 397 visited) { 398 unsigned int oldpos, size; 399 400 if ((strcmp(t->target.u.user.name, 401 ARPT_STANDARD_TARGET) == 0) && 402 t->verdict < -NF_MAX_VERDICT - 1) { 403 duprintf("mark_source_chains: bad " 404 "negative verdict (%i)\n", 405 t->verdict); 406 return 0; 407 } 408 409 /* Return: backtrack through the last 410 * big jump. 411 */ 412 do { 413 e->comefrom ^= (1<<NF_ARP_NUMHOOKS); 414 oldpos = pos; 415 pos = e->counters.pcnt; 416 e->counters.pcnt = 0; 417 418 /* We're at the start. */ 419 if (pos == oldpos) 420 goto next; 421 422 e = (struct arpt_entry *) 423 (entry0 + pos); 424 } while (oldpos == pos + e->next_offset); 425 426 /* Move along one */ 427 size = e->next_offset; 428 e = (struct arpt_entry *) 429 (entry0 + pos + size); 430 e->counters.pcnt = pos; 431 pos += size; 432 } else { 433 int newpos = t->verdict; 434 435 if (strcmp(t->target.u.user.name, 436 ARPT_STANDARD_TARGET) == 0 && 437 newpos >= 0) { 438 if (newpos > newinfo->size - 439 sizeof(struct arpt_entry)) { 440 duprintf("mark_source_chains: " 441 "bad verdict (%i)\n", 442 newpos); 443 return 0; 444 } 445 446 /* This a jump; chase it. */ 447 duprintf("Jump rule %u -> %u\n", 448 pos, newpos); 449 } else { 450 /* ... this is a fallthru */ 451 newpos = pos + e->next_offset; 452 } 453 e = (struct arpt_entry *) 454 (entry0 + newpos); 455 e->counters.pcnt = pos; 456 pos = newpos; 457 } 458 } 459 next: 460 duprintf("Finished chain %u\n", hook); 461 } 462 return 1; 463} 464 465static inline int check_entry(const struct arpt_entry *e, const char *name) 466{ 467 const struct arpt_entry_target *t; 468 469 if (!arp_checkentry(&e->arp)) { 470 duprintf("arp_tables: arp check failed %p %s.\n", e, name); 471 return -EINVAL; 472 } 473 474 if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset) 475 return -EINVAL; 476 477 t = arpt_get_target_c(e); 478 if (e->target_offset + t->u.target_size > e->next_offset) 479 return -EINVAL; 480 481 return 0; 482} 483 484static inline int check_target(struct arpt_entry *e, const char *name) 485{ 486 struct arpt_entry_target *t = arpt_get_target(e); 487 int ret; 488 struct xt_tgchk_param par = { 489 .table = name, 490 .entryinfo = e, 491 .target = t->u.kernel.target, 492 .targinfo = t->data, 493 .hook_mask = e->comefrom, 494 .family = NFPROTO_ARP, 495 }; 496 497 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false); 498 if (ret < 0) { 499 duprintf("arp_tables: check failed for `%s'.\n", 500 t->u.kernel.target->name); 501 return ret; 502 } 503 return 0; 504} 505 506static inline int 507find_check_entry(struct arpt_entry *e, const char *name, unsigned int size) 508{ 509 struct arpt_entry_target *t; 510 struct xt_target *target; 511 int ret; 512 513 ret = check_entry(e, name); 514 if (ret) 515 return ret; 516 517 t = arpt_get_target(e); 518 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name, 519 t->u.user.revision); 520 if (IS_ERR(target)) { 521 duprintf("find_check_entry: `%s' not found\n", t->u.user.name); 522 ret = PTR_ERR(target); 523 goto out; 524 } 525 t->u.kernel.target = target; 526 527 ret = check_target(e, name); 528 if (ret) 529 goto err; 530 return 0; 531err: 532 module_put(t->u.kernel.target->me); 533out: 534 return ret; 535} 536 537static bool check_underflow(const struct arpt_entry *e) 538{ 539 const struct arpt_entry_target *t; 540 unsigned int verdict; 541 542 if (!unconditional(&e->arp)) 543 return false; 544 t = arpt_get_target_c(e); 545 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 546 return false; 547 verdict = ((struct arpt_standard_target *)t)->verdict; 548 verdict = -verdict - 1; 549 return verdict == NF_DROP || verdict == NF_ACCEPT; 550} 551 552static inline int check_entry_size_and_hooks(struct arpt_entry *e, 553 struct xt_table_info *newinfo, 554 const unsigned char *base, 555 const unsigned char *limit, 556 const unsigned int *hook_entries, 557 const unsigned int *underflows, 558 unsigned int valid_hooks) 559{ 560 unsigned int h; 561 562 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 || 563 (unsigned char *)e + sizeof(struct arpt_entry) >= 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 arpt_entry_target)) { 570 duprintf("checking: element %p size %u\n", 571 e, e->next_offset); 572 return -EINVAL; 573 } 574 575 /* Check hooks & underflows */ 576 for (h = 0; h < NF_ARP_NUMHOOKS; h++) { 577 if (!(valid_hooks & (1 << h))) 578 continue; 579 if ((unsigned char *)e - base == hook_entries[h]) 580 newinfo->hook_entry[h] = hook_entries[h]; 581 if ((unsigned char *)e - base == underflows[h]) { 582 if (!check_underflow(e)) { 583 pr_err("Underflows must be unconditional and " 584 "use the STANDARD target with " 585 "ACCEPT/DROP\n"); 586 return -EINVAL; 587 } 588 newinfo->underflow[h] = underflows[h]; 589 } 590 } 591 592 /* Clear counters and comefrom */ 593 e->counters = ((struct xt_counters) { 0, 0 }); 594 e->comefrom = 0; 595 return 0; 596} 597 598static inline void cleanup_entry(struct arpt_entry *e) 599{ 600 struct xt_tgdtor_param par; 601 struct arpt_entry_target *t; 602 603 t = arpt_get_target(e); 604 par.target = t->u.kernel.target; 605 par.targinfo = t->data; 606 par.family = NFPROTO_ARP; 607 if (par.target->destroy != NULL) 608 par.target->destroy(&par); 609 module_put(par.target->me); 610} 611 612/* Checks and translates the user-supplied table segment (held in 613 * newinfo). 614 */ 615static int translate_table(struct xt_table_info *newinfo, void *entry0, 616 const struct arpt_replace *repl) 617{ 618 struct arpt_entry *iter; 619 unsigned int i; 620 int ret = 0; 621 622 newinfo->size = repl->size; 623 newinfo->number = repl->num_entries; 624 625 /* Init all hooks to impossible value. */ 626 for (i = 0; i < NF_ARP_NUMHOOKS; i++) { 627 newinfo->hook_entry[i] = 0xFFFFFFFF; 628 newinfo->underflow[i] = 0xFFFFFFFF; 629 } 630 631 duprintf("translate_table: size %u\n", newinfo->size); 632 i = 0; 633 634 /* Walk through entries, checking offsets. */ 635 xt_entry_foreach(iter, entry0, newinfo->size) { 636 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 637 entry0 + repl->size, 638 repl->hook_entry, 639 repl->underflow, 640 repl->valid_hooks); 641 if (ret != 0) 642 break; 643 ++i; 644 if (strcmp(arpt_get_target(iter)->u.user.name, 645 XT_ERROR_TARGET) == 0) 646 ++newinfo->stacksize; 647 } 648 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret); 649 if (ret != 0) 650 return ret; 651 652 if (i != repl->num_entries) { 653 duprintf("translate_table: %u not %u entries\n", 654 i, repl->num_entries); 655 return -EINVAL; 656 } 657 658 /* Check hooks all assigned */ 659 for (i = 0; i < NF_ARP_NUMHOOKS; i++) { 660 /* Only hooks which are valid */ 661 if (!(repl->valid_hooks & (1 << i))) 662 continue; 663 if (newinfo->hook_entry[i] == 0xFFFFFFFF) { 664 duprintf("Invalid hook entry %u %u\n", 665 i, repl->hook_entry[i]); 666 return -EINVAL; 667 } 668 if (newinfo->underflow[i] == 0xFFFFFFFF) { 669 duprintf("Invalid underflow %u %u\n", 670 i, repl->underflow[i]); 671 return -EINVAL; 672 } 673 } 674 675 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) { 676 duprintf("Looping hook\n"); 677 return -ELOOP; 678 } 679 680 /* Finally, each sanity check must pass */ 681 i = 0; 682 xt_entry_foreach(iter, entry0, newinfo->size) { 683 ret = find_check_entry(iter, repl->name, repl->size); 684 if (ret != 0) 685 break; 686 ++i; 687 } 688 689 if (ret != 0) { 690 xt_entry_foreach(iter, entry0, newinfo->size) { 691 if (i-- == 0) 692 break; 693 cleanup_entry(iter); 694 } 695 return ret; 696 } 697 698 /* And one copy for every other CPU */ 699 for_each_possible_cpu(i) { 700 if (newinfo->entries[i] && newinfo->entries[i] != entry0) 701 memcpy(newinfo->entries[i], entry0, newinfo->size); 702 } 703 704 return ret; 705} 706 707static void get_counters(const struct xt_table_info *t, 708 struct xt_counters counters[]) 709{ 710 struct arpt_entry *iter; 711 unsigned int cpu; 712 unsigned int i; 713 unsigned int curcpu = get_cpu(); 714 715 /* Instead of clearing (by a previous call to memset()) 716 * the counters and using adds, we set the counters 717 * with data used by 'current' CPU 718 * 719 * Bottom half has to be disabled to prevent deadlock 720 * if new softirq were to run and call ipt_do_table 721 */ 722 local_bh_disable(); 723 i = 0; 724 xt_entry_foreach(iter, t->entries[curcpu], t->size) { 725 SET_COUNTER(counters[i], iter->counters.bcnt, 726 iter->counters.pcnt); 727 ++i; 728 } 729 local_bh_enable(); 730 /* Processing counters from other cpus, we can let bottom half enabled, 731 * (preemption is disabled) 732 */ 733 734 for_each_possible_cpu(cpu) { 735 if (cpu == curcpu) 736 continue; 737 i = 0; 738 local_bh_disable(); 739 xt_info_wrlock(cpu); 740 xt_entry_foreach(iter, t->entries[cpu], t->size) { 741 ADD_COUNTER(counters[i], iter->counters.bcnt, 742 iter->counters.pcnt); 743 ++i; 744 } 745 xt_info_wrunlock(cpu); 746 local_bh_enable(); 747 } 748 put_cpu(); 749} 750 751static struct xt_counters *alloc_counters(const struct xt_table *table) 752{ 753 unsigned int countersize; 754 struct xt_counters *counters; 755 const struct xt_table_info *private = table->private; 756 757 /* We need atomic snapshot of counters: rest doesn't change 758 * (other than comefrom, which userspace doesn't care 759 * about). 760 */ 761 countersize = sizeof(struct xt_counters) * private->number; 762 counters = vmalloc(countersize); 763 764 if (counters == NULL) 765 return ERR_PTR(-ENOMEM); 766 767 get_counters(private, counters); 768 769 return counters; 770} 771 772static int copy_entries_to_user(unsigned int total_size, 773 const struct xt_table *table, 774 void __user *userptr) 775{ 776 unsigned int off, num; 777 const struct arpt_entry *e; 778 struct xt_counters *counters; 779 struct xt_table_info *private = table->private; 780 int ret = 0; 781 void *loc_cpu_entry; 782 783 counters = alloc_counters(table); 784 if (IS_ERR(counters)) 785 return PTR_ERR(counters); 786 787 loc_cpu_entry = private->entries[raw_smp_processor_id()]; 788 /* ... then copy entire thing ... */ 789 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) { 790 ret = -EFAULT; 791 goto free_counters; 792 } 793 794 /* ... then go back and fix counters and names */ 795 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 796 const struct arpt_entry_target *t; 797 798 e = (struct arpt_entry *)(loc_cpu_entry + off); 799 if (copy_to_user(userptr + off 800 + offsetof(struct arpt_entry, counters), 801 &counters[num], 802 sizeof(counters[num])) != 0) { 803 ret = -EFAULT; 804 goto free_counters; 805 } 806 807 t = arpt_get_target_c(e); 808 if (copy_to_user(userptr + off + e->target_offset 809 + offsetof(struct arpt_entry_target, 810 u.user.name), 811 t->u.kernel.target->name, 812 strlen(t->u.kernel.target->name)+1) != 0) { 813 ret = -EFAULT; 814 goto free_counters; 815 } 816 } 817 818 free_counters: 819 vfree(counters); 820 return ret; 821} 822 823#ifdef CONFIG_COMPAT 824static void compat_standard_from_user(void *dst, const void *src) 825{ 826 int v = *(compat_int_t *)src; 827 828 if (v > 0) 829 v += xt_compat_calc_jump(NFPROTO_ARP, v); 830 memcpy(dst, &v, sizeof(v)); 831} 832 833static int compat_standard_to_user(void __user *dst, const void *src) 834{ 835 compat_int_t cv = *(int *)src; 836 837 if (cv > 0) 838 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv); 839 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 840} 841 842static int compat_calc_entry(const struct arpt_entry *e, 843 const struct xt_table_info *info, 844 const void *base, struct xt_table_info *newinfo) 845{ 846 const struct arpt_entry_target *t; 847 unsigned int entry_offset; 848 int off, i, ret; 849 850 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); 851 entry_offset = (void *)e - base; 852 853 t = arpt_get_target_c(e); 854 off += xt_compat_target_offset(t->u.kernel.target); 855 newinfo->size -= off; 856 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off); 857 if (ret) 858 return ret; 859 860 for (i = 0; i < NF_ARP_NUMHOOKS; i++) { 861 if (info->hook_entry[i] && 862 (e < (struct arpt_entry *)(base + info->hook_entry[i]))) 863 newinfo->hook_entry[i] -= off; 864 if (info->underflow[i] && 865 (e < (struct arpt_entry *)(base + info->underflow[i]))) 866 newinfo->underflow[i] -= off; 867 } 868 return 0; 869} 870 871static int compat_table_info(const struct xt_table_info *info, 872 struct xt_table_info *newinfo) 873{ 874 struct arpt_entry *iter; 875 void *loc_cpu_entry; 876 int ret; 877 878 if (!newinfo || !info) 879 return -EINVAL; 880 881 /* we dont care about newinfo->entries[] */ 882 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 883 newinfo->initial_entries = 0; 884 loc_cpu_entry = info->entries[raw_smp_processor_id()]; 885 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 886 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 887 if (ret != 0) 888 return ret; 889 } 890 return 0; 891} 892#endif 893 894static int get_info(struct net *net, void __user *user, 895 const int *len, int compat) 896{ 897 char name[ARPT_TABLE_MAXNAMELEN]; 898 struct xt_table *t; 899 int ret; 900 901 if (*len != sizeof(struct arpt_getinfo)) { 902 duprintf("length %u != %Zu\n", *len, 903 sizeof(struct arpt_getinfo)); 904 return -EINVAL; 905 } 906 907 if (copy_from_user(name, user, sizeof(name)) != 0) 908 return -EFAULT; 909 910 name[ARPT_TABLE_MAXNAMELEN-1] = '\0'; 911#ifdef CONFIG_COMPAT 912 if (compat) 913 xt_compat_lock(NFPROTO_ARP); 914#endif 915 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name), 916 "arptable_%s", name); 917 if (t && !IS_ERR(t)) { 918 struct arpt_getinfo info; 919 const struct xt_table_info *private = t->private; 920#ifdef CONFIG_COMPAT 921 struct xt_table_info tmp; 922 923 if (compat) { 924 ret = compat_table_info(private, &tmp); 925 xt_compat_flush_offsets(NFPROTO_ARP); 926 private = &tmp; 927 } 928#endif 929 info.valid_hooks = t->valid_hooks; 930 memcpy(info.hook_entry, private->hook_entry, 931 sizeof(info.hook_entry)); 932 memcpy(info.underflow, private->underflow, 933 sizeof(info.underflow)); 934 info.num_entries = private->number; 935 info.size = private->size; 936 strcpy(info.name, name); 937 938 if (copy_to_user(user, &info, *len) != 0) 939 ret = -EFAULT; 940 else 941 ret = 0; 942 xt_table_unlock(t); 943 module_put(t->me); 944 } else 945 ret = t ? PTR_ERR(t) : -ENOENT; 946#ifdef CONFIG_COMPAT 947 if (compat) 948 xt_compat_unlock(NFPROTO_ARP); 949#endif 950 return ret; 951} 952 953static int get_entries(struct net *net, struct arpt_get_entries __user *uptr, 954 const int *len) 955{ 956 int ret; 957 struct arpt_get_entries get; 958 struct xt_table *t; 959 960 if (*len < sizeof(get)) { 961 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get)); 962 return -EINVAL; 963 } 964 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 965 return -EFAULT; 966 if (*len != sizeof(struct arpt_get_entries) + get.size) { 967 duprintf("get_entries: %u != %Zu\n", *len, 968 sizeof(struct arpt_get_entries) + get.size); 969 return -EINVAL; 970 } 971 972 t = xt_find_table_lock(net, NFPROTO_ARP, get.name); 973 if (t && !IS_ERR(t)) { 974 const struct xt_table_info *private = t->private; 975 976 duprintf("t->private->number = %u\n", 977 private->number); 978 if (get.size == private->size) 979 ret = copy_entries_to_user(private->size, 980 t, uptr->entrytable); 981 else { 982 duprintf("get_entries: I've got %u not %u!\n", 983 private->size, get.size); 984 ret = -EAGAIN; 985 } 986 module_put(t->me); 987 xt_table_unlock(t); 988 } else 989 ret = t ? PTR_ERR(t) : -ENOENT; 990 991 return ret; 992} 993 994static int __do_replace(struct net *net, const char *name, 995 unsigned int valid_hooks, 996 struct xt_table_info *newinfo, 997 unsigned int num_counters, 998 void __user *counters_ptr) 999{ 1000 int ret; 1001 struct xt_table *t; 1002 struct xt_table_info *oldinfo; 1003 struct xt_counters *counters; 1004 void *loc_cpu_old_entry; 1005 struct arpt_entry *iter; 1006 1007 ret = 0; 1008 counters = vmalloc(num_counters * sizeof(struct xt_counters)); 1009 if (!counters) { 1010 ret = -ENOMEM; 1011 goto out; 1012 } 1013 1014 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name), 1015 "arptable_%s", name); 1016 if (!t || IS_ERR(t)) { 1017 ret = t ? PTR_ERR(t) : -ENOENT; 1018 goto free_newinfo_counters_untrans; 1019 } 1020 1021 /* You lied! */ 1022 if (valid_hooks != t->valid_hooks) { 1023 duprintf("Valid hook crap: %08X vs %08X\n", 1024 valid_hooks, t->valid_hooks); 1025 ret = -EINVAL; 1026 goto put_module; 1027 } 1028 1029 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1030 if (!oldinfo) 1031 goto put_module; 1032 1033 /* Update module usage count based on number of rules */ 1034 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n", 1035 oldinfo->number, oldinfo->initial_entries, newinfo->number); 1036 if ((oldinfo->number > oldinfo->initial_entries) || 1037 (newinfo->number <= oldinfo->initial_entries)) 1038 module_put(t->me); 1039 if ((oldinfo->number > oldinfo->initial_entries) && 1040 (newinfo->number <= oldinfo->initial_entries)) 1041 module_put(t->me); 1042 1043 /* Get the old counters, and synchronize with replace */ 1044 get_counters(oldinfo, counters); 1045 1046 /* Decrease module usage counts and free resource */ 1047 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()]; 1048 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size) 1049 cleanup_entry(iter); 1050 1051 xt_free_table_info(oldinfo); 1052 if (copy_to_user(counters_ptr, counters, 1053 sizeof(struct xt_counters) * num_counters) != 0) 1054 ret = -EFAULT; 1055 vfree(counters); 1056 xt_table_unlock(t); 1057 return ret; 1058 1059 put_module: 1060 module_put(t->me); 1061 xt_table_unlock(t); 1062 free_newinfo_counters_untrans: 1063 vfree(counters); 1064 out: 1065 return ret; 1066} 1067 1068static int do_replace(struct net *net, const void __user *user, 1069 unsigned int len) 1070{ 1071 int ret; 1072 struct arpt_replace tmp; 1073 struct xt_table_info *newinfo; 1074 void *loc_cpu_entry; 1075 struct arpt_entry *iter; 1076 1077 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1078 return -EFAULT; 1079 1080 /* overflow check */ 1081 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1082 return -ENOMEM; 1083 1084 newinfo = xt_alloc_table_info(tmp.size); 1085 if (!newinfo) 1086 return -ENOMEM; 1087 1088 /* choose the copy that is on our node/cpu */ 1089 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; 1090 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1091 tmp.size) != 0) { 1092 ret = -EFAULT; 1093 goto free_newinfo; 1094 } 1095 1096 ret = translate_table(newinfo, loc_cpu_entry, &tmp); 1097 if (ret != 0) 1098 goto free_newinfo; 1099 1100 duprintf("arp_tables: Translated table\n"); 1101 1102 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1103 tmp.num_counters, tmp.counters); 1104 if (ret) 1105 goto free_newinfo_untrans; 1106 return 0; 1107 1108 free_newinfo_untrans: 1109 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1110 cleanup_entry(iter); 1111 free_newinfo: 1112 xt_free_table_info(newinfo); 1113 return ret; 1114} 1115 1116static int do_add_counters(struct net *net, const void __user *user, 1117 unsigned int len, int compat) 1118{ 1119 unsigned int i, curcpu; 1120 struct xt_counters_info tmp; 1121 struct xt_counters *paddc; 1122 unsigned int num_counters; 1123 const char *name; 1124 int size; 1125 void *ptmp; 1126 struct xt_table *t; 1127 const struct xt_table_info *private; 1128 int ret = 0; 1129 void *loc_cpu_entry; 1130 struct arpt_entry *iter; 1131#ifdef CONFIG_COMPAT 1132 struct compat_xt_counters_info compat_tmp; 1133 1134 if (compat) { 1135 ptmp = &compat_tmp; 1136 size = sizeof(struct compat_xt_counters_info); 1137 } else 1138#endif 1139 { 1140 ptmp = &tmp; 1141 size = sizeof(struct xt_counters_info); 1142 } 1143 1144 if (copy_from_user(ptmp, user, size) != 0) 1145 return -EFAULT; 1146 1147#ifdef CONFIG_COMPAT 1148 if (compat) { 1149 num_counters = compat_tmp.num_counters; 1150 name = compat_tmp.name; 1151 } else 1152#endif 1153 { 1154 num_counters = tmp.num_counters; 1155 name = tmp.name; 1156 } 1157 1158 if (len != size + num_counters * sizeof(struct xt_counters)) 1159 return -EINVAL; 1160 1161 paddc = vmalloc(len - size); 1162 if (!paddc) 1163 return -ENOMEM; 1164 1165 if (copy_from_user(paddc, user + size, len - size) != 0) { 1166 ret = -EFAULT; 1167 goto free; 1168 } 1169 1170 t = xt_find_table_lock(net, NFPROTO_ARP, name); 1171 if (!t || IS_ERR(t)) { 1172 ret = t ? PTR_ERR(t) : -ENOENT; 1173 goto free; 1174 } 1175 1176 local_bh_disable(); 1177 private = t->private; 1178 if (private->number != num_counters) { 1179 ret = -EINVAL; 1180 goto unlock_up_free; 1181 } 1182 1183 i = 0; 1184 /* Choose the copy that is on our node */ 1185 curcpu = smp_processor_id(); 1186 loc_cpu_entry = private->entries[curcpu]; 1187 xt_info_wrlock(curcpu); 1188 xt_entry_foreach(iter, loc_cpu_entry, private->size) { 1189 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt); 1190 ++i; 1191 } 1192 xt_info_wrunlock(curcpu); 1193 unlock_up_free: 1194 local_bh_enable(); 1195 xt_table_unlock(t); 1196 module_put(t->me); 1197 free: 1198 vfree(paddc); 1199 1200 return ret; 1201} 1202 1203#ifdef CONFIG_COMPAT 1204static inline void compat_release_entry(struct compat_arpt_entry *e) 1205{ 1206 struct arpt_entry_target *t; 1207 1208 t = compat_arpt_get_target(e); 1209 module_put(t->u.kernel.target->me); 1210} 1211 1212static inline int 1213check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, 1214 struct xt_table_info *newinfo, 1215 unsigned int *size, 1216 const unsigned char *base, 1217 const unsigned char *limit, 1218 const unsigned int *hook_entries, 1219 const unsigned int *underflows, 1220 const char *name) 1221{ 1222 struct arpt_entry_target *t; 1223 struct xt_target *target; 1224 unsigned int entry_offset; 1225 int ret, off, h; 1226 1227 duprintf("check_compat_entry_size_and_hooks %p\n", e); 1228 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 || 1229 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) { 1230 duprintf("Bad offset %p, limit = %p\n", e, limit); 1231 return -EINVAL; 1232 } 1233 1234 if (e->next_offset < sizeof(struct compat_arpt_entry) + 1235 sizeof(struct compat_xt_entry_target)) { 1236 duprintf("checking: element %p size %u\n", 1237 e, e->next_offset); 1238 return -EINVAL; 1239 } 1240 1241 /* For purposes of check_entry casting the compat entry is fine */ 1242 ret = check_entry((struct arpt_entry *)e, name); 1243 if (ret) 1244 return ret; 1245 1246 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); 1247 entry_offset = (void *)e - (void *)base; 1248 1249 t = compat_arpt_get_target(e); 1250 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name, 1251 t->u.user.revision); 1252 if (IS_ERR(target)) { 1253 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n", 1254 t->u.user.name); 1255 ret = PTR_ERR(target); 1256 goto out; 1257 } 1258 t->u.kernel.target = target; 1259 1260 off += xt_compat_target_offset(target); 1261 *size += off; 1262 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off); 1263 if (ret) 1264 goto release_target; 1265 1266 /* Check hooks & underflows */ 1267 for (h = 0; h < NF_ARP_NUMHOOKS; h++) { 1268 if ((unsigned char *)e - base == hook_entries[h]) 1269 newinfo->hook_entry[h] = hook_entries[h]; 1270 if ((unsigned char *)e - base == underflows[h]) 1271 newinfo->underflow[h] = underflows[h]; 1272 } 1273 1274 /* Clear counters and comefrom */ 1275 memset(&e->counters, 0, sizeof(e->counters)); 1276 e->comefrom = 0; 1277 return 0; 1278 1279release_target: 1280 module_put(t->u.kernel.target->me); 1281out: 1282 return ret; 1283} 1284 1285static int 1286compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, 1287 unsigned int *size, const char *name, 1288 struct xt_table_info *newinfo, unsigned char *base) 1289{ 1290 struct arpt_entry_target *t; 1291 struct xt_target *target; 1292 struct arpt_entry *de; 1293 unsigned int origsize; 1294 int ret, h; 1295 1296 ret = 0; 1297 origsize = *size; 1298 de = (struct arpt_entry *)*dstptr; 1299 memcpy(de, e, sizeof(struct arpt_entry)); 1300 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1301 1302 *dstptr += sizeof(struct arpt_entry); 1303 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); 1304 1305 de->target_offset = e->target_offset - (origsize - *size); 1306 t = compat_arpt_get_target(e); 1307 target = t->u.kernel.target; 1308 xt_compat_target_from_user(t, dstptr, size); 1309 1310 de->next_offset = e->next_offset - (origsize - *size); 1311 for (h = 0; h < NF_ARP_NUMHOOKS; h++) { 1312 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1313 newinfo->hook_entry[h] -= origsize - *size; 1314 if ((unsigned char *)de - base < newinfo->underflow[h]) 1315 newinfo->underflow[h] -= origsize - *size; 1316 } 1317 return ret; 1318} 1319 1320static int translate_compat_table(const char *name, 1321 unsigned int valid_hooks, 1322 struct xt_table_info **pinfo, 1323 void **pentry0, 1324 unsigned int total_size, 1325 unsigned int number, 1326 unsigned int *hook_entries, 1327 unsigned int *underflows) 1328{ 1329 unsigned int i, j; 1330 struct xt_table_info *newinfo, *info; 1331 void *pos, *entry0, *entry1; 1332 struct compat_arpt_entry *iter0; 1333 struct arpt_entry *iter1; 1334 unsigned int size; 1335 int ret = 0; 1336 1337 info = *pinfo; 1338 entry0 = *pentry0; 1339 size = total_size; 1340 info->number = number; 1341 1342 /* Init all hooks to impossible value. */ 1343 for (i = 0; i < NF_ARP_NUMHOOKS; i++) { 1344 info->hook_entry[i] = 0xFFFFFFFF; 1345 info->underflow[i] = 0xFFFFFFFF; 1346 } 1347 1348 duprintf("translate_compat_table: size %u\n", info->size); 1349 j = 0; 1350 xt_compat_lock(NFPROTO_ARP); 1351 /* Walk through entries, checking offsets. */ 1352 xt_entry_foreach(iter0, entry0, total_size) { 1353 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1354 entry0, 1355 entry0 + total_size, 1356 hook_entries, 1357 underflows, 1358 name); 1359 if (ret != 0) 1360 goto out_unlock; 1361 ++j; 1362 } 1363 1364 ret = -EINVAL; 1365 if (j != number) { 1366 duprintf("translate_compat_table: %u not %u entries\n", 1367 j, number); 1368 goto out_unlock; 1369 } 1370 1371 /* Check hooks all assigned */ 1372 for (i = 0; i < NF_ARP_NUMHOOKS; i++) { 1373 /* Only hooks which are valid */ 1374 if (!(valid_hooks & (1 << i))) 1375 continue; 1376 if (info->hook_entry[i] == 0xFFFFFFFF) { 1377 duprintf("Invalid hook entry %u %u\n", 1378 i, hook_entries[i]); 1379 goto out_unlock; 1380 } 1381 if (info->underflow[i] == 0xFFFFFFFF) { 1382 duprintf("Invalid underflow %u %u\n", 1383 i, underflows[i]); 1384 goto out_unlock; 1385 } 1386 } 1387 1388 ret = -ENOMEM; 1389 newinfo = xt_alloc_table_info(size); 1390 if (!newinfo) 1391 goto out_unlock; 1392 1393 newinfo->number = number; 1394 for (i = 0; i < NF_ARP_NUMHOOKS; i++) { 1395 newinfo->hook_entry[i] = info->hook_entry[i]; 1396 newinfo->underflow[i] = info->underflow[i]; 1397 } 1398 entry1 = newinfo->entries[raw_smp_processor_id()]; 1399 pos = entry1; 1400 size = total_size; 1401 xt_entry_foreach(iter0, entry0, total_size) { 1402 ret = compat_copy_entry_from_user(iter0, &pos, &size, 1403 name, newinfo, entry1); 1404 if (ret != 0) 1405 break; 1406 } 1407 xt_compat_flush_offsets(NFPROTO_ARP); 1408 xt_compat_unlock(NFPROTO_ARP); 1409 if (ret) 1410 goto free_newinfo; 1411 1412 ret = -ELOOP; 1413 if (!mark_source_chains(newinfo, valid_hooks, entry1)) 1414 goto free_newinfo; 1415 1416 i = 0; 1417 xt_entry_foreach(iter1, entry1, newinfo->size) { 1418 ret = check_target(iter1, name); 1419 if (ret != 0) 1420 break; 1421 ++i; 1422 if (strcmp(arpt_get_target(iter1)->u.user.name, 1423 XT_ERROR_TARGET) == 0) 1424 ++newinfo->stacksize; 1425 } 1426 if (ret) { 1427 /* 1428 * The first i matches need cleanup_entry (calls ->destroy) 1429 * because they had called ->check already. The other j-i 1430 * entries need only release. 1431 */ 1432 int skip = i; 1433 j -= i; 1434 xt_entry_foreach(iter0, entry0, newinfo->size) { 1435 if (skip-- > 0) 1436 continue; 1437 if (j-- == 0) 1438 break; 1439 compat_release_entry(iter0); 1440 } 1441 xt_entry_foreach(iter1, entry1, newinfo->size) { 1442 if (i-- == 0) 1443 break; 1444 cleanup_entry(iter1); 1445 } 1446 xt_free_table_info(newinfo); 1447 return ret; 1448 } 1449 1450 /* And one copy for every other CPU */ 1451 for_each_possible_cpu(i) 1452 if (newinfo->entries[i] && newinfo->entries[i] != entry1) 1453 memcpy(newinfo->entries[i], entry1, newinfo->size); 1454 1455 *pinfo = newinfo; 1456 *pentry0 = entry1; 1457 xt_free_table_info(info); 1458 return 0; 1459 1460free_newinfo: 1461 xt_free_table_info(newinfo); 1462out: 1463 xt_entry_foreach(iter0, entry0, total_size) { 1464 if (j-- == 0) 1465 break; 1466 compat_release_entry(iter0); 1467 } 1468 return ret; 1469out_unlock: 1470 xt_compat_flush_offsets(NFPROTO_ARP); 1471 xt_compat_unlock(NFPROTO_ARP); 1472 goto out; 1473} 1474 1475struct compat_arpt_replace { 1476 char name[ARPT_TABLE_MAXNAMELEN]; 1477 u32 valid_hooks; 1478 u32 num_entries; 1479 u32 size; 1480 u32 hook_entry[NF_ARP_NUMHOOKS]; 1481 u32 underflow[NF_ARP_NUMHOOKS]; 1482 u32 num_counters; 1483 compat_uptr_t counters; 1484 struct compat_arpt_entry entries[0]; 1485}; 1486 1487static int compat_do_replace(struct net *net, void __user *user, 1488 unsigned int len) 1489{ 1490 int ret; 1491 struct compat_arpt_replace tmp; 1492 struct xt_table_info *newinfo; 1493 void *loc_cpu_entry; 1494 struct arpt_entry *iter; 1495 1496 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1497 return -EFAULT; 1498 1499 /* overflow check */ 1500 if (tmp.size >= INT_MAX / num_possible_cpus()) 1501 return -ENOMEM; 1502 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1503 return -ENOMEM; 1504 1505 newinfo = xt_alloc_table_info(tmp.size); 1506 if (!newinfo) 1507 return -ENOMEM; 1508 1509 /* choose the copy that is on our node/cpu */ 1510 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; 1511 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) { 1512 ret = -EFAULT; 1513 goto free_newinfo; 1514 } 1515 1516 ret = translate_compat_table(tmp.name, tmp.valid_hooks, 1517 &newinfo, &loc_cpu_entry, tmp.size, 1518 tmp.num_entries, tmp.hook_entry, 1519 tmp.underflow); 1520 if (ret != 0) 1521 goto free_newinfo; 1522 1523 duprintf("compat_do_replace: Translated table\n"); 1524 1525 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1526 tmp.num_counters, compat_ptr(tmp.counters)); 1527 if (ret) 1528 goto free_newinfo_untrans; 1529 return 0; 1530 1531 free_newinfo_untrans: 1532 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1533 cleanup_entry(iter); 1534 free_newinfo: 1535 xt_free_table_info(newinfo); 1536 return ret; 1537} 1538 1539static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, 1540 unsigned int len) 1541{ 1542 int ret; 1543 1544 if (!capable(CAP_NET_ADMIN)) 1545 return -EPERM; 1546 1547 switch (cmd) { 1548 case ARPT_SO_SET_REPLACE: 1549 ret = compat_do_replace(sock_net(sk), user, len); 1550 break; 1551 1552 case ARPT_SO_SET_ADD_COUNTERS: 1553 ret = do_add_counters(sock_net(sk), user, len, 1); 1554 break; 1555 1556 default: 1557 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd); 1558 ret = -EINVAL; 1559 } 1560 1561 return ret; 1562} 1563 1564static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr, 1565 compat_uint_t *size, 1566 struct xt_counters *counters, 1567 unsigned int i) 1568{ 1569 struct arpt_entry_target *t; 1570 struct compat_arpt_entry __user *ce; 1571 u_int16_t target_offset, next_offset; 1572 compat_uint_t origsize; 1573 int ret; 1574 1575 origsize = *size; 1576 ce = (struct compat_arpt_entry __user *)*dstptr; 1577 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 || 1578 copy_to_user(&ce->counters, &counters[i], 1579 sizeof(counters[i])) != 0) 1580 return -EFAULT; 1581 1582 *dstptr += sizeof(struct compat_arpt_entry); 1583 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); 1584 1585 target_offset = e->target_offset - (origsize - *size); 1586 1587 t = arpt_get_target(e); 1588 ret = xt_compat_target_to_user(t, dstptr, size); 1589 if (ret) 1590 return ret; 1591 next_offset = e->next_offset - (origsize - *size); 1592 if (put_user(target_offset, &ce->target_offset) != 0 || 1593 put_user(next_offset, &ce->next_offset) != 0) 1594 return -EFAULT; 1595 return 0; 1596} 1597 1598static int compat_copy_entries_to_user(unsigned int total_size, 1599 struct xt_table *table, 1600 void __user *userptr) 1601{ 1602 struct xt_counters *counters; 1603 const struct xt_table_info *private = table->private; 1604 void __user *pos; 1605 unsigned int size; 1606 int ret = 0; 1607 void *loc_cpu_entry; 1608 unsigned int i = 0; 1609 struct arpt_entry *iter; 1610 1611 counters = alloc_counters(table); 1612 if (IS_ERR(counters)) 1613 return PTR_ERR(counters); 1614 1615 /* choose the copy on our node/cpu */ 1616 loc_cpu_entry = private->entries[raw_smp_processor_id()]; 1617 pos = userptr; 1618 size = total_size; 1619 xt_entry_foreach(iter, loc_cpu_entry, total_size) { 1620 ret = compat_copy_entry_to_user(iter, &pos, 1621 &size, counters, i++); 1622 if (ret != 0) 1623 break; 1624 } 1625 vfree(counters); 1626 return ret; 1627} 1628 1629struct compat_arpt_get_entries { 1630 char name[ARPT_TABLE_MAXNAMELEN]; 1631 compat_uint_t size; 1632 struct compat_arpt_entry entrytable[0]; 1633}; 1634 1635static int compat_get_entries(struct net *net, 1636 struct compat_arpt_get_entries __user *uptr, 1637 int *len) 1638{ 1639 int ret; 1640 struct compat_arpt_get_entries get; 1641 struct xt_table *t; 1642 1643 if (*len < sizeof(get)) { 1644 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get)); 1645 return -EINVAL; 1646 } 1647 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1648 return -EFAULT; 1649 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) { 1650 duprintf("compat_get_entries: %u != %zu\n", 1651 *len, sizeof(get) + get.size); 1652 return -EINVAL; 1653 } 1654 1655 xt_compat_lock(NFPROTO_ARP); 1656 t = xt_find_table_lock(net, NFPROTO_ARP, get.name); 1657 if (t && !IS_ERR(t)) { 1658 const struct xt_table_info *private = t->private; 1659 struct xt_table_info info; 1660 1661 duprintf("t->private->number = %u\n", private->number); 1662 ret = compat_table_info(private, &info); 1663 if (!ret && get.size == info.size) { 1664 ret = compat_copy_entries_to_user(private->size, 1665 t, uptr->entrytable); 1666 } else if (!ret) { 1667 duprintf("compat_get_entries: I've got %u not %u!\n", 1668 private->size, get.size); 1669 ret = -EAGAIN; 1670 } 1671 xt_compat_flush_offsets(NFPROTO_ARP); 1672 module_put(t->me); 1673 xt_table_unlock(t); 1674 } else 1675 ret = t ? PTR_ERR(t) : -ENOENT; 1676 1677 xt_compat_unlock(NFPROTO_ARP); 1678 return ret; 1679} 1680 1681static int do_arpt_get_ctl(struct sock *, int, void __user *, int *); 1682 1683static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, 1684 int *len) 1685{ 1686 int ret; 1687 1688 if (!capable(CAP_NET_ADMIN)) 1689 return -EPERM; 1690 1691 switch (cmd) { 1692 case ARPT_SO_GET_INFO: 1693 ret = get_info(sock_net(sk), user, len, 1); 1694 break; 1695 case ARPT_SO_GET_ENTRIES: 1696 ret = compat_get_entries(sock_net(sk), user, len); 1697 break; 1698 default: 1699 ret = do_arpt_get_ctl(sk, cmd, user, len); 1700 } 1701 return ret; 1702} 1703#endif 1704 1705static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) 1706{ 1707 int ret; 1708 1709 if (!capable(CAP_NET_ADMIN)) 1710 return -EPERM; 1711 1712 switch (cmd) { 1713 case ARPT_SO_SET_REPLACE: 1714 ret = do_replace(sock_net(sk), user, len); 1715 break; 1716 1717 case ARPT_SO_SET_ADD_COUNTERS: 1718 ret = do_add_counters(sock_net(sk), user, len, 0); 1719 break; 1720 1721 default: 1722 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd); 1723 ret = -EINVAL; 1724 } 1725 1726 return ret; 1727} 1728 1729static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1730{ 1731 int ret; 1732 1733 if (!capable(CAP_NET_ADMIN)) 1734 return -EPERM; 1735 1736 switch (cmd) { 1737 case ARPT_SO_GET_INFO: 1738 ret = get_info(sock_net(sk), user, len, 0); 1739 break; 1740 1741 case ARPT_SO_GET_ENTRIES: 1742 ret = get_entries(sock_net(sk), user, len); 1743 break; 1744 1745 case ARPT_SO_GET_REVISION_TARGET: { 1746 struct xt_get_revision rev; 1747 1748 if (*len != sizeof(rev)) { 1749 ret = -EINVAL; 1750 break; 1751 } 1752 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1753 ret = -EFAULT; 1754 break; 1755 } 1756 1757 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name, 1758 rev.revision, 1, &ret), 1759 "arpt_%s", rev.name); 1760 break; 1761 } 1762 1763 default: 1764 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd); 1765 ret = -EINVAL; 1766 } 1767 1768 return ret; 1769} 1770 1771struct xt_table *arpt_register_table(struct net *net, 1772 const struct xt_table *table, 1773 const struct arpt_replace *repl) 1774{ 1775 int ret; 1776 struct xt_table_info *newinfo; 1777 struct xt_table_info bootstrap = {0}; 1778 void *loc_cpu_entry; 1779 struct xt_table *new_table; 1780 1781 newinfo = xt_alloc_table_info(repl->size); 1782 if (!newinfo) { 1783 ret = -ENOMEM; 1784 goto out; 1785 } 1786 1787 /* choose the copy on our node/cpu */ 1788 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; 1789 memcpy(loc_cpu_entry, repl->entries, repl->size); 1790 1791 ret = translate_table(newinfo, loc_cpu_entry, repl); 1792 duprintf("arpt_register_table: translate table gives %d\n", ret); 1793 if (ret != 0) 1794 goto out_free; 1795 1796 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1797 if (IS_ERR(new_table)) { 1798 ret = PTR_ERR(new_table); 1799 goto out_free; 1800 } 1801 return new_table; 1802 1803out_free: 1804 xt_free_table_info(newinfo); 1805out: 1806 return ERR_PTR(ret); 1807} 1808 1809void arpt_unregister_table(struct xt_table *table) 1810{ 1811 struct xt_table_info *private; 1812 void *loc_cpu_entry; 1813 struct module *table_owner = table->me; 1814 struct arpt_entry *iter; 1815 1816 private = xt_unregister_table(table); 1817 1818 /* Decrease module usage counts and free resources */ 1819 loc_cpu_entry = private->entries[raw_smp_processor_id()]; 1820 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1821 cleanup_entry(iter); 1822 if (private->number > private->initial_entries) 1823 module_put(table_owner); 1824 xt_free_table_info(private); 1825} 1826 1827/* The built-in targets: standard (NULL) and error. */ 1828static struct xt_target arpt_builtin_tg[] __read_mostly = { 1829 { 1830 .name = ARPT_STANDARD_TARGET, 1831 .targetsize = sizeof(int), 1832 .family = NFPROTO_ARP, 1833#ifdef CONFIG_COMPAT 1834 .compatsize = sizeof(compat_int_t), 1835 .compat_from_user = compat_standard_from_user, 1836 .compat_to_user = compat_standard_to_user, 1837#endif 1838 }, 1839 { 1840 .name = ARPT_ERROR_TARGET, 1841 .target = arpt_error, 1842 .targetsize = ARPT_FUNCTION_MAXNAMELEN, 1843 .family = NFPROTO_ARP, 1844 }, 1845}; 1846 1847static struct nf_sockopt_ops arpt_sockopts = { 1848 .pf = PF_INET, 1849 .set_optmin = ARPT_BASE_CTL, 1850 .set_optmax = ARPT_SO_SET_MAX+1, 1851 .set = do_arpt_set_ctl, 1852#ifdef CONFIG_COMPAT 1853 .compat_set = compat_do_arpt_set_ctl, 1854#endif 1855 .get_optmin = ARPT_BASE_CTL, 1856 .get_optmax = ARPT_SO_GET_MAX+1, 1857 .get = do_arpt_get_ctl, 1858#ifdef CONFIG_COMPAT 1859 .compat_get = compat_do_arpt_get_ctl, 1860#endif 1861 .owner = THIS_MODULE, 1862}; 1863 1864static int __net_init arp_tables_net_init(struct net *net) 1865{ 1866 return xt_proto_init(net, NFPROTO_ARP); 1867} 1868 1869static void __net_exit arp_tables_net_exit(struct net *net) 1870{ 1871 xt_proto_fini(net, NFPROTO_ARP); 1872} 1873 1874static struct pernet_operations arp_tables_net_ops = { 1875 .init = arp_tables_net_init, 1876 .exit = arp_tables_net_exit, 1877}; 1878 1879static int __init arp_tables_init(void) 1880{ 1881 int ret; 1882 1883 ret = register_pernet_subsys(&arp_tables_net_ops); 1884 if (ret < 0) 1885 goto err1; 1886 1887 /* Noone else will be downing sem now, so we won't sleep */ 1888 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg)); 1889 if (ret < 0) 1890 goto err2; 1891 1892 /* Register setsockopt */ 1893 ret = nf_register_sockopt(&arpt_sockopts); 1894 if (ret < 0) 1895 goto err4; 1896 1897 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n"); 1898 return 0; 1899 1900err4: 1901 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg)); 1902err2: 1903 unregister_pernet_subsys(&arp_tables_net_ops); 1904err1: 1905 return ret; 1906} 1907 1908static void __exit arp_tables_fini(void) 1909{ 1910 nf_unregister_sockopt(&arpt_sockopts); 1911 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg)); 1912 unregister_pernet_subsys(&arp_tables_net_ops); 1913} 1914 1915EXPORT_SYMBOL(arpt_register_table); 1916EXPORT_SYMBOL(arpt_unregister_table); 1917EXPORT_SYMBOL(arpt_do_table); 1918 1919module_init(arp_tables_init); 1920module_exit(arp_tables_fini); 1921