1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Packet matching code. 4 * 5 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 6 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> 7 * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net> 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/kernel.h> 13 #include <linux/capability.h> 14 #include <linux/in.h> 15 #include <linux/skbuff.h> 16 #include <linux/kmod.h> 17 #include <linux/vmalloc.h> 18 #include <linux/netdevice.h> 19 #include <linux/module.h> 20 #include <linux/poison.h> 21 #include <linux/icmpv6.h> 22 #include <net/ipv6.h> 23 #include <net/compat.h> 24 #include <linux/uaccess.h> 25 #include <linux/mutex.h> 26 #include <linux/proc_fs.h> 27 #include <linux/err.h> 28 #include <linux/cpumask.h> 29 30 #include <linux/netfilter_ipv6/ip6_tables.h> 31 #include <linux/netfilter/x_tables.h> 32 #include <net/netfilter/nf_log.h> 33 #include "../../netfilter/xt_repldata.h" 34 35 MODULE_LICENSE("GPL"); 36 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 37 MODULE_DESCRIPTION("IPv6 packet filter"); 38 MODULE_ALIAS("ip6t_icmp6"); 39 40 void *ip6t_alloc_initial_table(const struct xt_table *info) 41 { 42 return xt_alloc_initial_table(ip6t, IP6T); 43 } 44 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table); 45 46 /* Returns whether matches rule or not. */ 47 /* Performance critical - called for every packet */ 48 static inline bool 49 ip6_packet_match(const struct sk_buff *skb, 50 const char *indev, 51 const char *outdev, 52 const struct ip6t_ip6 *ip6info, 53 unsigned int *protoff, 54 u16 *fragoff, bool *hotdrop) 55 { 56 unsigned long ret; 57 const struct ipv6hdr *ipv6 = ipv6_hdr(skb); 58 59 if (NF_INVF(ip6info, IP6T_INV_SRCIP, 60 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, 61 &ip6info->src)) || 62 NF_INVF(ip6info, IP6T_INV_DSTIP, 63 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, 64 &ip6info->dst))) 65 return false; 66 67 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask); 68 69 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0)) 70 return false; 71 72 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask); 73 74 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0)) 75 return false; 76 77 /* ... might want to do something with class and flowlabel here ... */ 78 79 /* look for the desired protocol header */ 80 if (ip6info->flags & IP6T_F_PROTO) { 81 int protohdr; 82 unsigned short _frag_off; 83 84 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); 85 if (protohdr < 0) { 86 if (_frag_off == 0) 87 *hotdrop = true; 88 return false; 89 } 90 *fragoff = _frag_off; 91 92 if (ip6info->proto == protohdr) { 93 if (ip6info->invflags & IP6T_INV_PROTO) 94 return false; 95 96 return true; 97 } 98 99 /* We need match for the '-p all', too! */ 100 if ((ip6info->proto != 0) && 101 !(ip6info->invflags & IP6T_INV_PROTO)) 102 return false; 103 } 104 return true; 105 } 106 107 /* should be ip6 safe */ 108 static bool 109 ip6_checkentry(const struct ip6t_ip6 *ipv6) 110 { 111 if (ipv6->flags & ~IP6T_F_MASK) 112 return false; 113 if (ipv6->invflags & ~IP6T_INV_MASK) 114 return false; 115 116 return true; 117 } 118 119 static unsigned int 120 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par) 121 { 122 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 123 124 return NF_DROP; 125 } 126 127 static inline struct ip6t_entry * 128 get_entry(const void *base, unsigned int offset) 129 { 130 return (struct ip6t_entry *)(base + offset); 131 } 132 133 /* All zeroes == unconditional rule. */ 134 /* Mildly perf critical (only if packet tracing is on) */ 135 static inline bool unconditional(const struct ip6t_entry *e) 136 { 137 static const struct ip6t_ip6 uncond; 138 139 return e->target_offset == sizeof(struct ip6t_entry) && 140 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0; 141 } 142 143 static inline const struct xt_entry_target * 144 ip6t_get_target_c(const struct ip6t_entry *e) 145 { 146 return ip6t_get_target((struct ip6t_entry *)e); 147 } 148 149 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 150 /* This cries for unification! */ 151 static const char *const hooknames[] = { 152 [NF_INET_PRE_ROUTING] = "PREROUTING", 153 [NF_INET_LOCAL_IN] = "INPUT", 154 [NF_INET_FORWARD] = "FORWARD", 155 [NF_INET_LOCAL_OUT] = "OUTPUT", 156 [NF_INET_POST_ROUTING] = "POSTROUTING", 157 }; 158 159 enum nf_ip_trace_comments { 160 NF_IP6_TRACE_COMMENT_RULE, 161 NF_IP6_TRACE_COMMENT_RETURN, 162 NF_IP6_TRACE_COMMENT_POLICY, 163 }; 164 165 static const char *const comments[] = { 166 [NF_IP6_TRACE_COMMENT_RULE] = "rule", 167 [NF_IP6_TRACE_COMMENT_RETURN] = "return", 168 [NF_IP6_TRACE_COMMENT_POLICY] = "policy", 169 }; 170 171 static const struct nf_loginfo trace_loginfo = { 172 .type = NF_LOG_TYPE_LOG, 173 .u = { 174 .log = { 175 .level = LOGLEVEL_WARNING, 176 .logflags = NF_LOG_DEFAULT_MASK, 177 }, 178 }, 179 }; 180 181 /* Mildly perf critical (only if packet tracing is on) */ 182 static inline int 183 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e, 184 const char *hookname, const char **chainname, 185 const char **comment, unsigned int *rulenum) 186 { 187 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s); 188 189 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 190 /* Head of user chain: ERROR target with chainname */ 191 *chainname = t->target.data; 192 (*rulenum) = 0; 193 } else if (s == e) { 194 (*rulenum)++; 195 196 if (unconditional(s) && 197 strcmp(t->target.u.kernel.target->name, 198 XT_STANDARD_TARGET) == 0 && 199 t->verdict < 0) { 200 /* Tail of chains: STANDARD target (return/policy) */ 201 *comment = *chainname == hookname 202 ? comments[NF_IP6_TRACE_COMMENT_POLICY] 203 : comments[NF_IP6_TRACE_COMMENT_RETURN]; 204 } 205 return 1; 206 } else 207 (*rulenum)++; 208 209 return 0; 210 } 211 212 static void trace_packet(struct net *net, 213 const struct sk_buff *skb, 214 unsigned int hook, 215 const struct net_device *in, 216 const struct net_device *out, 217 const char *tablename, 218 const struct xt_table_info *private, 219 const struct ip6t_entry *e) 220 { 221 const struct ip6t_entry *root; 222 const char *hookname, *chainname, *comment; 223 const struct ip6t_entry *iter; 224 unsigned int rulenum = 0; 225 226 root = get_entry(private->entries, private->hook_entry[hook]); 227 228 hookname = chainname = hooknames[hook]; 229 comment = comments[NF_IP6_TRACE_COMMENT_RULE]; 230 231 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 232 if (get_chainname_rulenum(iter, e, hookname, 233 &chainname, &comment, &rulenum) != 0) 234 break; 235 236 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo, 237 "TRACE: %s:%s:%s:%u ", 238 tablename, chainname, comment, rulenum); 239 } 240 #endif 241 242 static inline struct ip6t_entry * 243 ip6t_next_entry(const struct ip6t_entry *entry) 244 { 245 return (void *)entry + entry->next_offset; 246 } 247 248 /* Returns one of the generic firewall policies, like NF_ACCEPT. */ 249 unsigned int 250 ip6t_do_table(void *priv, struct sk_buff *skb, 251 const struct nf_hook_state *state) 252 { 253 const struct xt_table *table = priv; 254 unsigned int hook = state->hook; 255 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 256 /* Initializing verdict to NF_DROP keeps gcc happy. */ 257 unsigned int verdict = NF_DROP; 258 const char *indev, *outdev; 259 const void *table_base; 260 struct ip6t_entry *e, **jumpstack; 261 unsigned int stackidx, cpu; 262 const struct xt_table_info *private; 263 struct xt_action_param acpar; 264 unsigned int addend; 265 266 /* Initialization */ 267 stackidx = 0; 268 indev = state->in ? state->in->name : nulldevname; 269 outdev = state->out ? state->out->name : nulldevname; 270 /* We handle fragments by dealing with the first fragment as 271 * if it was a normal packet. All other fragments are treated 272 * normally, except that they will NEVER match rules that ask 273 * things we don't know, ie. tcp syn flag or ports). If the 274 * rule is also a fragment-specific rule, non-fragments won't 275 * match it. */ 276 acpar.fragoff = 0; 277 acpar.hotdrop = false; 278 acpar.state = state; 279 280 WARN_ON(!(table->valid_hooks & (1 << hook))); 281 282 local_bh_disable(); 283 addend = xt_write_recseq_begin(); 284 private = READ_ONCE(table->private); /* Address dependency. */ 285 cpu = smp_processor_id(); 286 table_base = private->entries; 287 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 288 289 /* Switch to alternate jumpstack if we're being invoked via TEE. 290 * TEE issues XT_CONTINUE verdict on original skb so we must not 291 * clobber the jumpstack. 292 * 293 * For recursion via REJECT or SYNPROXY the stack will be clobbered 294 * but it is no problem since absolute verdict is issued by these. 295 */ 296 if (static_key_false(&xt_tee_enabled)) 297 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); 298 299 e = get_entry(table_base, private->hook_entry[hook]); 300 301 do { 302 const struct xt_entry_target *t; 303 const struct xt_entry_match *ematch; 304 struct xt_counters *counter; 305 306 WARN_ON(!e); 307 acpar.thoff = 0; 308 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 309 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 310 no_match: 311 e = ip6t_next_entry(e); 312 continue; 313 } 314 315 xt_ematch_foreach(ematch, e) { 316 acpar.match = ematch->u.kernel.match; 317 acpar.matchinfo = ematch->data; 318 if (!acpar.match->match(skb, &acpar)) 319 goto no_match; 320 } 321 322 counter = xt_get_this_cpu_counter(&e->counters); 323 ADD_COUNTER(*counter, skb->len, 1); 324 325 t = ip6t_get_target_c(e); 326 WARN_ON(!t->u.kernel.target); 327 328 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 329 /* The packet is traced: log it */ 330 if (unlikely(skb->nf_trace)) 331 trace_packet(state->net, skb, hook, state->in, 332 state->out, table->name, private, e); 333 #endif 334 /* Standard target? */ 335 if (!t->u.kernel.target->target) { 336 int v; 337 338 v = ((struct xt_standard_target *)t)->verdict; 339 if (v < 0) { 340 /* Pop from stack? */ 341 if (v != XT_RETURN) { 342 verdict = (unsigned int)(-v) - 1; 343 break; 344 } 345 if (stackidx == 0) 346 e = get_entry(table_base, 347 private->underflow[hook]); 348 else 349 e = ip6t_next_entry(jumpstack[--stackidx]); 350 continue; 351 } 352 if (table_base + v != ip6t_next_entry(e) && 353 !(e->ipv6.flags & IP6T_F_GOTO)) { 354 if (unlikely(stackidx >= private->stacksize)) { 355 verdict = NF_DROP; 356 break; 357 } 358 jumpstack[stackidx++] = e; 359 } 360 361 e = get_entry(table_base, v); 362 continue; 363 } 364 365 acpar.target = t->u.kernel.target; 366 acpar.targinfo = t->data; 367 368 verdict = t->u.kernel.target->target(skb, &acpar); 369 if (verdict == XT_CONTINUE) 370 e = ip6t_next_entry(e); 371 else 372 /* Verdict */ 373 break; 374 } while (!acpar.hotdrop); 375 376 xt_write_recseq_end(addend); 377 local_bh_enable(); 378 379 if (acpar.hotdrop) 380 return NF_DROP; 381 else return verdict; 382 } 383 384 /* Figures out from what hook each rule can be called: returns 0 if 385 there are loops. Puts hook bitmask in comefrom. */ 386 static int 387 mark_source_chains(const struct xt_table_info *newinfo, 388 unsigned int valid_hooks, void *entry0, 389 unsigned int *offsets) 390 { 391 unsigned int hook; 392 393 /* No recursion; use packet counter to save back ptrs (reset 394 to 0 as we leave), and comefrom to save source hook bitmask */ 395 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 396 unsigned int pos = newinfo->hook_entry[hook]; 397 struct ip6t_entry *e = entry0 + pos; 398 399 if (!(valid_hooks & (1 << hook))) 400 continue; 401 402 /* Set initial back pointer. */ 403 e->counters.pcnt = pos; 404 405 for (;;) { 406 const struct xt_standard_target *t 407 = (void *)ip6t_get_target_c(e); 408 int visited = e->comefrom & (1 << hook); 409 410 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 411 return 0; 412 413 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 414 415 /* Unconditional return/END. */ 416 if ((unconditional(e) && 417 (strcmp(t->target.u.user.name, 418 XT_STANDARD_TARGET) == 0) && 419 t->verdict < 0) || visited) { 420 unsigned int oldpos, size; 421 422 /* Return: backtrack through the last 423 big jump. */ 424 do { 425 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 426 oldpos = pos; 427 pos = e->counters.pcnt; 428 e->counters.pcnt = 0; 429 430 /* We're at the start. */ 431 if (pos == oldpos) 432 goto next; 433 434 e = entry0 + pos; 435 } while (oldpos == pos + e->next_offset); 436 437 /* Move along one */ 438 size = e->next_offset; 439 e = entry0 + pos + size; 440 if (pos + size >= newinfo->size) 441 return 0; 442 e->counters.pcnt = pos; 443 pos += size; 444 } else { 445 int newpos = t->verdict; 446 447 if (strcmp(t->target.u.user.name, 448 XT_STANDARD_TARGET) == 0 && 449 newpos >= 0) { 450 /* This a jump; chase it. */ 451 if (!xt_find_jump_offset(offsets, newpos, 452 newinfo->number)) 453 return 0; 454 } else { 455 /* ... this is a fallthru */ 456 newpos = pos + e->next_offset; 457 if (newpos >= newinfo->size) 458 return 0; 459 } 460 e = entry0 + newpos; 461 e->counters.pcnt = pos; 462 pos = newpos; 463 } 464 } 465 next: ; 466 } 467 return 1; 468 } 469 470 static void cleanup_match(struct xt_entry_match *m, struct net *net) 471 { 472 struct xt_mtdtor_param par; 473 474 par.net = net; 475 par.match = m->u.kernel.match; 476 par.matchinfo = m->data; 477 par.family = NFPROTO_IPV6; 478 if (par.match->destroy != NULL) 479 par.match->destroy(&par); 480 module_put(par.match->me); 481 } 482 483 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 484 { 485 const struct ip6t_ip6 *ipv6 = par->entryinfo; 486 487 par->match = m->u.kernel.match; 488 par->matchinfo = m->data; 489 490 return xt_check_match(par, m->u.match_size - sizeof(*m), 491 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 492 } 493 494 static int 495 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 496 { 497 struct xt_match *match; 498 int ret; 499 500 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 501 m->u.user.revision); 502 if (IS_ERR(match)) 503 return PTR_ERR(match); 504 505 m->u.kernel.match = match; 506 507 ret = check_match(m, par); 508 if (ret) 509 goto err; 510 511 return 0; 512 err: 513 module_put(m->u.kernel.match->me); 514 return ret; 515 } 516 517 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 518 { 519 struct xt_entry_target *t = ip6t_get_target(e); 520 struct xt_tgchk_param par = { 521 .net = net, 522 .table = name, 523 .entryinfo = e, 524 .target = t->u.kernel.target, 525 .targinfo = t->data, 526 .hook_mask = e->comefrom, 527 .family = NFPROTO_IPV6, 528 }; 529 530 return xt_check_target(&par, t->u.target_size - sizeof(*t), 531 e->ipv6.proto, 532 e->ipv6.invflags & IP6T_INV_PROTO); 533 } 534 535 static int 536 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 537 unsigned int size, 538 struct xt_percpu_counter_alloc_state *alloc_state) 539 { 540 struct xt_entry_target *t; 541 struct xt_target *target; 542 int ret; 543 unsigned int j; 544 struct xt_mtchk_param mtpar; 545 struct xt_entry_match *ematch; 546 547 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 548 return -ENOMEM; 549 550 j = 0; 551 memset(&mtpar, 0, sizeof(mtpar)); 552 mtpar.net = net; 553 mtpar.table = name; 554 mtpar.entryinfo = &e->ipv6; 555 mtpar.hook_mask = e->comefrom; 556 mtpar.family = NFPROTO_IPV6; 557 xt_ematch_foreach(ematch, e) { 558 ret = find_check_match(ematch, &mtpar); 559 if (ret != 0) 560 goto cleanup_matches; 561 ++j; 562 } 563 564 t = ip6t_get_target(e); 565 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 566 t->u.user.revision); 567 if (IS_ERR(target)) { 568 ret = PTR_ERR(target); 569 goto cleanup_matches; 570 } 571 t->u.kernel.target = target; 572 573 ret = check_target(e, net, name); 574 if (ret) 575 goto err; 576 return 0; 577 err: 578 module_put(t->u.kernel.target->me); 579 cleanup_matches: 580 xt_ematch_foreach(ematch, e) { 581 if (j-- == 0) 582 break; 583 cleanup_match(ematch, net); 584 } 585 586 xt_percpu_counter_free(&e->counters); 587 588 return ret; 589 } 590 591 static bool check_underflow(const struct ip6t_entry *e) 592 { 593 const struct xt_entry_target *t; 594 unsigned int verdict; 595 596 if (!unconditional(e)) 597 return false; 598 t = ip6t_get_target_c(e); 599 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 600 return false; 601 verdict = ((struct xt_standard_target *)t)->verdict; 602 verdict = -verdict - 1; 603 return verdict == NF_DROP || verdict == NF_ACCEPT; 604 } 605 606 static int 607 check_entry_size_and_hooks(struct ip6t_entry *e, 608 struct xt_table_info *newinfo, 609 const unsigned char *base, 610 const unsigned char *limit, 611 const unsigned int *hook_entries, 612 const unsigned int *underflows, 613 unsigned int valid_hooks) 614 { 615 unsigned int h; 616 int err; 617 618 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 619 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 620 (unsigned char *)e + e->next_offset > limit) 621 return -EINVAL; 622 623 if (e->next_offset 624 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 625 return -EINVAL; 626 627 if (!ip6_checkentry(&e->ipv6)) 628 return -EINVAL; 629 630 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 631 e->next_offset); 632 if (err) 633 return err; 634 635 /* Check hooks & underflows */ 636 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 637 if (!(valid_hooks & (1 << h))) 638 continue; 639 if ((unsigned char *)e - base == hook_entries[h]) 640 newinfo->hook_entry[h] = hook_entries[h]; 641 if ((unsigned char *)e - base == underflows[h]) { 642 if (!check_underflow(e)) 643 return -EINVAL; 644 645 newinfo->underflow[h] = underflows[h]; 646 } 647 } 648 649 /* Clear counters and comefrom */ 650 e->counters = ((struct xt_counters) { 0, 0 }); 651 e->comefrom = 0; 652 return 0; 653 } 654 655 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 656 { 657 struct xt_tgdtor_param par; 658 struct xt_entry_target *t; 659 struct xt_entry_match *ematch; 660 661 /* Cleanup all matches */ 662 xt_ematch_foreach(ematch, e) 663 cleanup_match(ematch, net); 664 t = ip6t_get_target(e); 665 666 par.net = net; 667 par.target = t->u.kernel.target; 668 par.targinfo = t->data; 669 par.family = NFPROTO_IPV6; 670 if (par.target->destroy != NULL) 671 par.target->destroy(&par); 672 module_put(par.target->me); 673 xt_percpu_counter_free(&e->counters); 674 } 675 676 /* Checks and translates the user-supplied table segment (held in 677 newinfo) */ 678 static int 679 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 680 const struct ip6t_replace *repl) 681 { 682 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 683 struct ip6t_entry *iter; 684 unsigned int *offsets; 685 unsigned int i; 686 int ret = 0; 687 688 newinfo->size = repl->size; 689 newinfo->number = repl->num_entries; 690 691 /* Init all hooks to impossible value. */ 692 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 693 newinfo->hook_entry[i] = 0xFFFFFFFF; 694 newinfo->underflow[i] = 0xFFFFFFFF; 695 } 696 697 offsets = xt_alloc_entry_offsets(newinfo->number); 698 if (!offsets) 699 return -ENOMEM; 700 i = 0; 701 /* Walk through entries, checking offsets. */ 702 xt_entry_foreach(iter, entry0, newinfo->size) { 703 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 704 entry0 + repl->size, 705 repl->hook_entry, 706 repl->underflow, 707 repl->valid_hooks); 708 if (ret != 0) 709 goto out_free; 710 if (i < repl->num_entries) 711 offsets[i] = (void *)iter - entry0; 712 ++i; 713 if (strcmp(ip6t_get_target(iter)->u.user.name, 714 XT_ERROR_TARGET) == 0) 715 ++newinfo->stacksize; 716 } 717 718 ret = -EINVAL; 719 if (i != repl->num_entries) 720 goto out_free; 721 722 ret = xt_check_table_hooks(newinfo, repl->valid_hooks); 723 if (ret) 724 goto out_free; 725 726 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 727 ret = -ELOOP; 728 goto out_free; 729 } 730 kvfree(offsets); 731 732 /* Finally, each sanity check must pass */ 733 i = 0; 734 xt_entry_foreach(iter, entry0, newinfo->size) { 735 ret = find_check_entry(iter, net, repl->name, repl->size, 736 &alloc_state); 737 if (ret != 0) 738 break; 739 ++i; 740 } 741 742 if (ret != 0) { 743 xt_entry_foreach(iter, entry0, newinfo->size) { 744 if (i-- == 0) 745 break; 746 cleanup_entry(iter, net); 747 } 748 return ret; 749 } 750 751 return ret; 752 out_free: 753 kvfree(offsets); 754 return ret; 755 } 756 757 static void 758 get_counters(const struct xt_table_info *t, 759 struct xt_counters counters[]) 760 { 761 struct ip6t_entry *iter; 762 unsigned int cpu; 763 unsigned int i; 764 765 for_each_possible_cpu(cpu) { 766 seqcount_t *s = &per_cpu(xt_recseq, cpu); 767 768 i = 0; 769 xt_entry_foreach(iter, t->entries, t->size) { 770 struct xt_counters *tmp; 771 u64 bcnt, pcnt; 772 unsigned int start; 773 774 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 775 do { 776 start = read_seqcount_begin(s); 777 bcnt = tmp->bcnt; 778 pcnt = tmp->pcnt; 779 } while (read_seqcount_retry(s, start)); 780 781 ADD_COUNTER(counters[i], bcnt, pcnt); 782 ++i; 783 cond_resched(); 784 } 785 } 786 } 787 788 static void get_old_counters(const struct xt_table_info *t, 789 struct xt_counters counters[]) 790 { 791 struct ip6t_entry *iter; 792 unsigned int cpu, i; 793 794 for_each_possible_cpu(cpu) { 795 i = 0; 796 xt_entry_foreach(iter, t->entries, t->size) { 797 const struct xt_counters *tmp; 798 799 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 800 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 801 ++i; 802 } 803 cond_resched(); 804 } 805 } 806 807 static struct xt_counters *alloc_counters(const struct xt_table *table) 808 { 809 unsigned int countersize; 810 struct xt_counters *counters; 811 const struct xt_table_info *private = table->private; 812 813 /* We need atomic snapshot of counters: rest doesn't change 814 (other than comefrom, which userspace doesn't care 815 about). */ 816 countersize = sizeof(struct xt_counters) * private->number; 817 counters = vzalloc(countersize); 818 819 if (counters == NULL) 820 return ERR_PTR(-ENOMEM); 821 822 get_counters(private, counters); 823 824 return counters; 825 } 826 827 static int 828 copy_entries_to_user(unsigned int total_size, 829 const struct xt_table *table, 830 void __user *userptr) 831 { 832 unsigned int off, num; 833 const struct ip6t_entry *e; 834 struct xt_counters *counters; 835 const struct xt_table_info *private = table->private; 836 int ret = 0; 837 const void *loc_cpu_entry; 838 839 counters = alloc_counters(table); 840 if (IS_ERR(counters)) 841 return PTR_ERR(counters); 842 843 loc_cpu_entry = private->entries; 844 845 /* FIXME: use iterator macros --RR */ 846 /* ... then go back and fix counters and names */ 847 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 848 unsigned int i; 849 const struct xt_entry_match *m; 850 const struct xt_entry_target *t; 851 852 e = loc_cpu_entry + off; 853 if (copy_to_user(userptr + off, e, sizeof(*e))) { 854 ret = -EFAULT; 855 goto free_counters; 856 } 857 if (copy_to_user(userptr + off 858 + offsetof(struct ip6t_entry, counters), 859 &counters[num], 860 sizeof(counters[num])) != 0) { 861 ret = -EFAULT; 862 goto free_counters; 863 } 864 865 for (i = sizeof(struct ip6t_entry); 866 i < e->target_offset; 867 i += m->u.match_size) { 868 m = (void *)e + i; 869 870 if (xt_match_to_user(m, userptr + off + i)) { 871 ret = -EFAULT; 872 goto free_counters; 873 } 874 } 875 876 t = ip6t_get_target_c(e); 877 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 878 ret = -EFAULT; 879 goto free_counters; 880 } 881 } 882 883 free_counters: 884 vfree(counters); 885 return ret; 886 } 887 888 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 889 static void compat_standard_from_user(void *dst, const void *src) 890 { 891 int v = *(compat_int_t *)src; 892 893 if (v > 0) 894 v += xt_compat_calc_jump(AF_INET6, v); 895 memcpy(dst, &v, sizeof(v)); 896 } 897 898 static int compat_standard_to_user(void __user *dst, const void *src) 899 { 900 compat_int_t cv = *(int *)src; 901 902 if (cv > 0) 903 cv -= xt_compat_calc_jump(AF_INET6, cv); 904 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 905 } 906 907 static int compat_calc_entry(const struct ip6t_entry *e, 908 const struct xt_table_info *info, 909 const void *base, struct xt_table_info *newinfo) 910 { 911 const struct xt_entry_match *ematch; 912 const struct xt_entry_target *t; 913 unsigned int entry_offset; 914 int off, i, ret; 915 916 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 917 entry_offset = (void *)e - base; 918 xt_ematch_foreach(ematch, e) 919 off += xt_compat_match_offset(ematch->u.kernel.match); 920 t = ip6t_get_target_c(e); 921 off += xt_compat_target_offset(t->u.kernel.target); 922 newinfo->size -= off; 923 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 924 if (ret) 925 return ret; 926 927 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 928 if (info->hook_entry[i] && 929 (e < (struct ip6t_entry *)(base + info->hook_entry[i]))) 930 newinfo->hook_entry[i] -= off; 931 if (info->underflow[i] && 932 (e < (struct ip6t_entry *)(base + info->underflow[i]))) 933 newinfo->underflow[i] -= off; 934 } 935 return 0; 936 } 937 938 static int compat_table_info(const struct xt_table_info *info, 939 struct xt_table_info *newinfo) 940 { 941 struct ip6t_entry *iter; 942 const void *loc_cpu_entry; 943 int ret; 944 945 if (!newinfo || !info) 946 return -EINVAL; 947 948 /* we dont care about newinfo->entries */ 949 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 950 newinfo->initial_entries = 0; 951 loc_cpu_entry = info->entries; 952 ret = xt_compat_init_offsets(AF_INET6, info->number); 953 if (ret) 954 return ret; 955 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 956 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 957 if (ret != 0) 958 return ret; 959 } 960 return 0; 961 } 962 #endif 963 964 static int get_info(struct net *net, void __user *user, const int *len) 965 { 966 char name[XT_TABLE_MAXNAMELEN]; 967 struct xt_table *t; 968 int ret; 969 970 if (*len != sizeof(struct ip6t_getinfo)) 971 return -EINVAL; 972 973 if (copy_from_user(name, user, sizeof(name)) != 0) 974 return -EFAULT; 975 976 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 977 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 978 if (in_compat_syscall()) 979 xt_compat_lock(AF_INET6); 980 #endif 981 t = xt_request_find_table_lock(net, AF_INET6, name); 982 if (!IS_ERR(t)) { 983 struct ip6t_getinfo info; 984 const struct xt_table_info *private = t->private; 985 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 986 struct xt_table_info tmp; 987 988 if (in_compat_syscall()) { 989 ret = compat_table_info(private, &tmp); 990 xt_compat_flush_offsets(AF_INET6); 991 private = &tmp; 992 } 993 #endif 994 memset(&info, 0, sizeof(info)); 995 info.valid_hooks = t->valid_hooks; 996 memcpy(info.hook_entry, private->hook_entry, 997 sizeof(info.hook_entry)); 998 memcpy(info.underflow, private->underflow, 999 sizeof(info.underflow)); 1000 info.num_entries = private->number; 1001 info.size = private->size; 1002 strcpy(info.name, name); 1003 1004 if (copy_to_user(user, &info, *len) != 0) 1005 ret = -EFAULT; 1006 else 1007 ret = 0; 1008 1009 xt_table_unlock(t); 1010 module_put(t->me); 1011 } else 1012 ret = PTR_ERR(t); 1013 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1014 if (in_compat_syscall()) 1015 xt_compat_unlock(AF_INET6); 1016 #endif 1017 return ret; 1018 } 1019 1020 static int 1021 get_entries(struct net *net, struct ip6t_get_entries __user *uptr, 1022 const int *len) 1023 { 1024 int ret; 1025 struct ip6t_get_entries get; 1026 struct xt_table *t; 1027 1028 if (*len < sizeof(get)) 1029 return -EINVAL; 1030 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1031 return -EFAULT; 1032 if (*len != sizeof(struct ip6t_get_entries) + get.size) 1033 return -EINVAL; 1034 1035 get.name[sizeof(get.name) - 1] = '\0'; 1036 1037 t = xt_find_table_lock(net, AF_INET6, get.name); 1038 if (!IS_ERR(t)) { 1039 struct xt_table_info *private = t->private; 1040 if (get.size == private->size) 1041 ret = copy_entries_to_user(private->size, 1042 t, uptr->entrytable); 1043 else 1044 ret = -EAGAIN; 1045 1046 module_put(t->me); 1047 xt_table_unlock(t); 1048 } else 1049 ret = PTR_ERR(t); 1050 1051 return ret; 1052 } 1053 1054 static int 1055 __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1056 struct xt_table_info *newinfo, unsigned int num_counters, 1057 void __user *counters_ptr) 1058 { 1059 int ret; 1060 struct xt_table *t; 1061 struct xt_table_info *oldinfo; 1062 struct xt_counters *counters; 1063 struct ip6t_entry *iter; 1064 1065 ret = 0; 1066 counters = xt_counters_alloc(num_counters); 1067 if (!counters) { 1068 ret = -ENOMEM; 1069 goto out; 1070 } 1071 1072 t = xt_request_find_table_lock(net, AF_INET6, name); 1073 if (IS_ERR(t)) { 1074 ret = PTR_ERR(t); 1075 goto free_newinfo_counters_untrans; 1076 } 1077 1078 /* You lied! */ 1079 if (valid_hooks != t->valid_hooks) { 1080 ret = -EINVAL; 1081 goto put_module; 1082 } 1083 1084 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1085 if (!oldinfo) 1086 goto put_module; 1087 1088 /* Update module usage count based on number of rules */ 1089 if ((oldinfo->number > oldinfo->initial_entries) || 1090 (newinfo->number <= oldinfo->initial_entries)) 1091 module_put(t->me); 1092 if ((oldinfo->number > oldinfo->initial_entries) && 1093 (newinfo->number <= oldinfo->initial_entries)) 1094 module_put(t->me); 1095 1096 xt_table_unlock(t); 1097 1098 get_old_counters(oldinfo, counters); 1099 1100 /* Decrease module usage counts and free resource */ 1101 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1102 cleanup_entry(iter, net); 1103 1104 xt_free_table_info(oldinfo); 1105 if (copy_to_user(counters_ptr, counters, 1106 sizeof(struct xt_counters) * num_counters) != 0) { 1107 /* Silent error, can't fail, new table is already in place */ 1108 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1109 } 1110 vfree(counters); 1111 return ret; 1112 1113 put_module: 1114 module_put(t->me); 1115 xt_table_unlock(t); 1116 free_newinfo_counters_untrans: 1117 vfree(counters); 1118 out: 1119 return ret; 1120 } 1121 1122 static int 1123 do_replace(struct net *net, sockptr_t arg, unsigned int len) 1124 { 1125 int ret; 1126 struct ip6t_replace tmp; 1127 struct xt_table_info *newinfo; 1128 void *loc_cpu_entry; 1129 struct ip6t_entry *iter; 1130 1131 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1132 return -EFAULT; 1133 1134 /* overflow check */ 1135 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1136 return -ENOMEM; 1137 if (tmp.num_counters == 0) 1138 return -EINVAL; 1139 1140 tmp.name[sizeof(tmp.name)-1] = 0; 1141 1142 newinfo = xt_alloc_table_info(tmp.size); 1143 if (!newinfo) 1144 return -ENOMEM; 1145 1146 loc_cpu_entry = newinfo->entries; 1147 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1148 tmp.size) != 0) { 1149 ret = -EFAULT; 1150 goto free_newinfo; 1151 } 1152 1153 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1154 if (ret != 0) 1155 goto free_newinfo; 1156 1157 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1158 tmp.num_counters, tmp.counters); 1159 if (ret) 1160 goto free_newinfo_untrans; 1161 return 0; 1162 1163 free_newinfo_untrans: 1164 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1165 cleanup_entry(iter, net); 1166 free_newinfo: 1167 xt_free_table_info(newinfo); 1168 return ret; 1169 } 1170 1171 static int 1172 do_add_counters(struct net *net, sockptr_t arg, unsigned int len) 1173 { 1174 unsigned int i; 1175 struct xt_counters_info tmp; 1176 struct xt_counters *paddc; 1177 struct xt_table *t; 1178 const struct xt_table_info *private; 1179 int ret = 0; 1180 struct ip6t_entry *iter; 1181 unsigned int addend; 1182 1183 paddc = xt_copy_counters(arg, len, &tmp); 1184 if (IS_ERR(paddc)) 1185 return PTR_ERR(paddc); 1186 t = xt_find_table_lock(net, AF_INET6, tmp.name); 1187 if (IS_ERR(t)) { 1188 ret = PTR_ERR(t); 1189 goto free; 1190 } 1191 1192 local_bh_disable(); 1193 private = t->private; 1194 if (private->number != tmp.num_counters) { 1195 ret = -EINVAL; 1196 goto unlock_up_free; 1197 } 1198 1199 i = 0; 1200 addend = xt_write_recseq_begin(); 1201 xt_entry_foreach(iter, private->entries, private->size) { 1202 struct xt_counters *tmp; 1203 1204 tmp = xt_get_this_cpu_counter(&iter->counters); 1205 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); 1206 ++i; 1207 } 1208 xt_write_recseq_end(addend); 1209 unlock_up_free: 1210 local_bh_enable(); 1211 xt_table_unlock(t); 1212 module_put(t->me); 1213 free: 1214 vfree(paddc); 1215 1216 return ret; 1217 } 1218 1219 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1220 struct compat_ip6t_replace { 1221 char name[XT_TABLE_MAXNAMELEN]; 1222 u32 valid_hooks; 1223 u32 num_entries; 1224 u32 size; 1225 u32 hook_entry[NF_INET_NUMHOOKS]; 1226 u32 underflow[NF_INET_NUMHOOKS]; 1227 u32 num_counters; 1228 compat_uptr_t counters; /* struct xt_counters * */ 1229 struct compat_ip6t_entry entries[]; 1230 }; 1231 1232 static int 1233 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr, 1234 unsigned int *size, struct xt_counters *counters, 1235 unsigned int i) 1236 { 1237 struct xt_entry_target *t; 1238 struct compat_ip6t_entry __user *ce; 1239 u_int16_t target_offset, next_offset; 1240 compat_uint_t origsize; 1241 const struct xt_entry_match *ematch; 1242 int ret = 0; 1243 1244 origsize = *size; 1245 ce = *dstptr; 1246 if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 || 1247 copy_to_user(&ce->counters, &counters[i], 1248 sizeof(counters[i])) != 0) 1249 return -EFAULT; 1250 1251 *dstptr += sizeof(struct compat_ip6t_entry); 1252 *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1253 1254 xt_ematch_foreach(ematch, e) { 1255 ret = xt_compat_match_to_user(ematch, dstptr, size); 1256 if (ret != 0) 1257 return ret; 1258 } 1259 target_offset = e->target_offset - (origsize - *size); 1260 t = ip6t_get_target(e); 1261 ret = xt_compat_target_to_user(t, dstptr, size); 1262 if (ret) 1263 return ret; 1264 next_offset = e->next_offset - (origsize - *size); 1265 if (put_user(target_offset, &ce->target_offset) != 0 || 1266 put_user(next_offset, &ce->next_offset) != 0) 1267 return -EFAULT; 1268 return 0; 1269 } 1270 1271 static int 1272 compat_find_calc_match(struct xt_entry_match *m, 1273 const struct ip6t_ip6 *ipv6, 1274 int *size) 1275 { 1276 struct xt_match *match; 1277 1278 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 1279 m->u.user.revision); 1280 if (IS_ERR(match)) 1281 return PTR_ERR(match); 1282 1283 m->u.kernel.match = match; 1284 *size += xt_compat_match_offset(match); 1285 return 0; 1286 } 1287 1288 static void compat_release_entry(struct compat_ip6t_entry *e) 1289 { 1290 struct xt_entry_target *t; 1291 struct xt_entry_match *ematch; 1292 1293 /* Cleanup all matches */ 1294 xt_ematch_foreach(ematch, e) 1295 module_put(ematch->u.kernel.match->me); 1296 t = compat_ip6t_get_target(e); 1297 module_put(t->u.kernel.target->me); 1298 } 1299 1300 static int 1301 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, 1302 struct xt_table_info *newinfo, 1303 unsigned int *size, 1304 const unsigned char *base, 1305 const unsigned char *limit) 1306 { 1307 struct xt_entry_match *ematch; 1308 struct xt_entry_target *t; 1309 struct xt_target *target; 1310 unsigned int entry_offset; 1311 unsigned int j; 1312 int ret, off; 1313 1314 if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 || 1315 (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit || 1316 (unsigned char *)e + e->next_offset > limit) 1317 return -EINVAL; 1318 1319 if (e->next_offset < sizeof(struct compat_ip6t_entry) + 1320 sizeof(struct compat_xt_entry_target)) 1321 return -EINVAL; 1322 1323 if (!ip6_checkentry(&e->ipv6)) 1324 return -EINVAL; 1325 1326 ret = xt_compat_check_entry_offsets(e, e->elems, 1327 e->target_offset, e->next_offset); 1328 if (ret) 1329 return ret; 1330 1331 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1332 entry_offset = (void *)e - (void *)base; 1333 j = 0; 1334 xt_ematch_foreach(ematch, e) { 1335 ret = compat_find_calc_match(ematch, &e->ipv6, &off); 1336 if (ret != 0) 1337 goto release_matches; 1338 ++j; 1339 } 1340 1341 t = compat_ip6t_get_target(e); 1342 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 1343 t->u.user.revision); 1344 if (IS_ERR(target)) { 1345 ret = PTR_ERR(target); 1346 goto release_matches; 1347 } 1348 t->u.kernel.target = target; 1349 1350 off += xt_compat_target_offset(target); 1351 *size += off; 1352 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 1353 if (ret) 1354 goto out; 1355 1356 return 0; 1357 1358 out: 1359 module_put(t->u.kernel.target->me); 1360 release_matches: 1361 xt_ematch_foreach(ematch, e) { 1362 if (j-- == 0) 1363 break; 1364 module_put(ematch->u.kernel.match->me); 1365 } 1366 return ret; 1367 } 1368 1369 static void 1370 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, 1371 unsigned int *size, 1372 struct xt_table_info *newinfo, unsigned char *base) 1373 { 1374 struct xt_entry_target *t; 1375 struct ip6t_entry *de; 1376 unsigned int origsize; 1377 int h; 1378 struct xt_entry_match *ematch; 1379 1380 origsize = *size; 1381 de = *dstptr; 1382 memcpy(de, e, sizeof(struct ip6t_entry)); 1383 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1384 1385 *dstptr += sizeof(struct ip6t_entry); 1386 *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1387 1388 xt_ematch_foreach(ematch, e) 1389 xt_compat_match_from_user(ematch, dstptr, size); 1390 1391 de->target_offset = e->target_offset - (origsize - *size); 1392 t = compat_ip6t_get_target(e); 1393 xt_compat_target_from_user(t, dstptr, size); 1394 1395 de->next_offset = e->next_offset - (origsize - *size); 1396 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 1397 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1398 newinfo->hook_entry[h] -= origsize - *size; 1399 if ((unsigned char *)de - base < newinfo->underflow[h]) 1400 newinfo->underflow[h] -= origsize - *size; 1401 } 1402 } 1403 1404 static int 1405 translate_compat_table(struct net *net, 1406 struct xt_table_info **pinfo, 1407 void **pentry0, 1408 const struct compat_ip6t_replace *compatr) 1409 { 1410 unsigned int i, j; 1411 struct xt_table_info *newinfo, *info; 1412 void *pos, *entry0, *entry1; 1413 struct compat_ip6t_entry *iter0; 1414 struct ip6t_replace repl; 1415 unsigned int size; 1416 int ret; 1417 1418 info = *pinfo; 1419 entry0 = *pentry0; 1420 size = compatr->size; 1421 info->number = compatr->num_entries; 1422 1423 j = 0; 1424 xt_compat_lock(AF_INET6); 1425 ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries); 1426 if (ret) 1427 goto out_unlock; 1428 /* Walk through entries, checking offsets. */ 1429 xt_entry_foreach(iter0, entry0, compatr->size) { 1430 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1431 entry0, 1432 entry0 + compatr->size); 1433 if (ret != 0) 1434 goto out_unlock; 1435 ++j; 1436 } 1437 1438 ret = -EINVAL; 1439 if (j != compatr->num_entries) 1440 goto out_unlock; 1441 1442 ret = -ENOMEM; 1443 newinfo = xt_alloc_table_info(size); 1444 if (!newinfo) 1445 goto out_unlock; 1446 1447 memset(newinfo->entries, 0, size); 1448 1449 newinfo->number = compatr->num_entries; 1450 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1451 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1452 newinfo->underflow[i] = compatr->underflow[i]; 1453 } 1454 entry1 = newinfo->entries; 1455 pos = entry1; 1456 size = compatr->size; 1457 xt_entry_foreach(iter0, entry0, compatr->size) 1458 compat_copy_entry_from_user(iter0, &pos, &size, 1459 newinfo, entry1); 1460 1461 /* all module references in entry0 are now gone. */ 1462 xt_compat_flush_offsets(AF_INET6); 1463 xt_compat_unlock(AF_INET6); 1464 1465 memcpy(&repl, compatr, sizeof(*compatr)); 1466 1467 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1468 repl.hook_entry[i] = newinfo->hook_entry[i]; 1469 repl.underflow[i] = newinfo->underflow[i]; 1470 } 1471 1472 repl.num_counters = 0; 1473 repl.counters = NULL; 1474 repl.size = newinfo->size; 1475 ret = translate_table(net, newinfo, entry1, &repl); 1476 if (ret) 1477 goto free_newinfo; 1478 1479 *pinfo = newinfo; 1480 *pentry0 = entry1; 1481 xt_free_table_info(info); 1482 return 0; 1483 1484 free_newinfo: 1485 xt_free_table_info(newinfo); 1486 return ret; 1487 out_unlock: 1488 xt_compat_flush_offsets(AF_INET6); 1489 xt_compat_unlock(AF_INET6); 1490 xt_entry_foreach(iter0, entry0, compatr->size) { 1491 if (j-- == 0) 1492 break; 1493 compat_release_entry(iter0); 1494 } 1495 return ret; 1496 } 1497 1498 static int 1499 compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) 1500 { 1501 int ret; 1502 struct compat_ip6t_replace tmp; 1503 struct xt_table_info *newinfo; 1504 void *loc_cpu_entry; 1505 struct ip6t_entry *iter; 1506 1507 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1508 return -EFAULT; 1509 1510 /* overflow check */ 1511 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1512 return -ENOMEM; 1513 if (tmp.num_counters == 0) 1514 return -EINVAL; 1515 1516 tmp.name[sizeof(tmp.name)-1] = 0; 1517 1518 newinfo = xt_alloc_table_info(tmp.size); 1519 if (!newinfo) 1520 return -ENOMEM; 1521 1522 loc_cpu_entry = newinfo->entries; 1523 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1524 tmp.size) != 0) { 1525 ret = -EFAULT; 1526 goto free_newinfo; 1527 } 1528 1529 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1530 if (ret != 0) 1531 goto free_newinfo; 1532 1533 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1534 tmp.num_counters, compat_ptr(tmp.counters)); 1535 if (ret) 1536 goto free_newinfo_untrans; 1537 return 0; 1538 1539 free_newinfo_untrans: 1540 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1541 cleanup_entry(iter, net); 1542 free_newinfo: 1543 xt_free_table_info(newinfo); 1544 return ret; 1545 } 1546 1547 struct compat_ip6t_get_entries { 1548 char name[XT_TABLE_MAXNAMELEN]; 1549 compat_uint_t size; 1550 struct compat_ip6t_entry entrytable[]; 1551 }; 1552 1553 static int 1554 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1555 void __user *userptr) 1556 { 1557 struct xt_counters *counters; 1558 const struct xt_table_info *private = table->private; 1559 void __user *pos; 1560 unsigned int size; 1561 int ret = 0; 1562 unsigned int i = 0; 1563 struct ip6t_entry *iter; 1564 1565 counters = alloc_counters(table); 1566 if (IS_ERR(counters)) 1567 return PTR_ERR(counters); 1568 1569 pos = userptr; 1570 size = total_size; 1571 xt_entry_foreach(iter, private->entries, total_size) { 1572 ret = compat_copy_entry_to_user(iter, &pos, 1573 &size, counters, i++); 1574 if (ret != 0) 1575 break; 1576 } 1577 1578 vfree(counters); 1579 return ret; 1580 } 1581 1582 static int 1583 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1584 int *len) 1585 { 1586 int ret; 1587 struct compat_ip6t_get_entries get; 1588 struct xt_table *t; 1589 1590 if (*len < sizeof(get)) 1591 return -EINVAL; 1592 1593 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1594 return -EFAULT; 1595 1596 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1597 return -EINVAL; 1598 1599 get.name[sizeof(get.name) - 1] = '\0'; 1600 1601 xt_compat_lock(AF_INET6); 1602 t = xt_find_table_lock(net, AF_INET6, get.name); 1603 if (!IS_ERR(t)) { 1604 const struct xt_table_info *private = t->private; 1605 struct xt_table_info info; 1606 ret = compat_table_info(private, &info); 1607 if (!ret && get.size == info.size) 1608 ret = compat_copy_entries_to_user(private->size, 1609 t, uptr->entrytable); 1610 else if (!ret) 1611 ret = -EAGAIN; 1612 1613 xt_compat_flush_offsets(AF_INET6); 1614 module_put(t->me); 1615 xt_table_unlock(t); 1616 } else 1617 ret = PTR_ERR(t); 1618 1619 xt_compat_unlock(AF_INET6); 1620 return ret; 1621 } 1622 #endif 1623 1624 static int 1625 do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len) 1626 { 1627 int ret; 1628 1629 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1630 return -EPERM; 1631 1632 switch (cmd) { 1633 case IP6T_SO_SET_REPLACE: 1634 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1635 if (in_compat_syscall()) 1636 ret = compat_do_replace(sock_net(sk), arg, len); 1637 else 1638 #endif 1639 ret = do_replace(sock_net(sk), arg, len); 1640 break; 1641 1642 case IP6T_SO_SET_ADD_COUNTERS: 1643 ret = do_add_counters(sock_net(sk), arg, len); 1644 break; 1645 1646 default: 1647 ret = -EINVAL; 1648 } 1649 1650 return ret; 1651 } 1652 1653 static int 1654 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1655 { 1656 int ret; 1657 1658 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1659 return -EPERM; 1660 1661 switch (cmd) { 1662 case IP6T_SO_GET_INFO: 1663 ret = get_info(sock_net(sk), user, len); 1664 break; 1665 1666 case IP6T_SO_GET_ENTRIES: 1667 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1668 if (in_compat_syscall()) 1669 ret = compat_get_entries(sock_net(sk), user, len); 1670 else 1671 #endif 1672 ret = get_entries(sock_net(sk), user, len); 1673 break; 1674 1675 case IP6T_SO_GET_REVISION_MATCH: 1676 case IP6T_SO_GET_REVISION_TARGET: { 1677 struct xt_get_revision rev; 1678 int target; 1679 1680 if (*len != sizeof(rev)) { 1681 ret = -EINVAL; 1682 break; 1683 } 1684 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1685 ret = -EFAULT; 1686 break; 1687 } 1688 rev.name[sizeof(rev.name)-1] = 0; 1689 1690 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1691 target = 1; 1692 else 1693 target = 0; 1694 1695 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1696 rev.revision, 1697 target, &ret), 1698 "ip6t_%s", rev.name); 1699 break; 1700 } 1701 1702 default: 1703 ret = -EINVAL; 1704 } 1705 1706 return ret; 1707 } 1708 1709 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1710 { 1711 struct xt_table_info *private; 1712 void *loc_cpu_entry; 1713 struct module *table_owner = table->me; 1714 struct ip6t_entry *iter; 1715 1716 private = xt_unregister_table(table); 1717 1718 /* Decrease module usage counts and free resources */ 1719 loc_cpu_entry = private->entries; 1720 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1721 cleanup_entry(iter, net); 1722 if (private->number > private->initial_entries) 1723 module_put(table_owner); 1724 xt_free_table_info(private); 1725 } 1726 1727 int ip6t_register_table(struct net *net, const struct xt_table *table, 1728 const struct ip6t_replace *repl, 1729 const struct nf_hook_ops *template_ops) 1730 { 1731 struct nf_hook_ops *ops; 1732 unsigned int num_ops; 1733 int ret, i; 1734 struct xt_table_info *newinfo; 1735 struct xt_table_info bootstrap = {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 return -ENOMEM; 1742 1743 loc_cpu_entry = newinfo->entries; 1744 memcpy(loc_cpu_entry, repl->entries, repl->size); 1745 1746 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1747 if (ret != 0) { 1748 xt_free_table_info(newinfo); 1749 return ret; 1750 } 1751 1752 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1753 if (IS_ERR(new_table)) { 1754 xt_free_table_info(newinfo); 1755 return PTR_ERR(new_table); 1756 } 1757 1758 if (!template_ops) 1759 return 0; 1760 1761 num_ops = hweight32(table->valid_hooks); 1762 if (num_ops == 0) { 1763 ret = -EINVAL; 1764 goto out_free; 1765 } 1766 1767 ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL); 1768 if (!ops) { 1769 ret = -ENOMEM; 1770 goto out_free; 1771 } 1772 1773 for (i = 0; i < num_ops; i++) 1774 ops[i].priv = new_table; 1775 1776 new_table->ops = ops; 1777 1778 ret = nf_register_net_hooks(net, ops, num_ops); 1779 if (ret != 0) 1780 goto out_free; 1781 1782 return ret; 1783 1784 out_free: 1785 __ip6t_unregister_table(net, new_table); 1786 return ret; 1787 } 1788 1789 void ip6t_unregister_table_pre_exit(struct net *net, const char *name) 1790 { 1791 struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name); 1792 1793 if (table) 1794 nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks)); 1795 } 1796 1797 void ip6t_unregister_table_exit(struct net *net, const char *name) 1798 { 1799 struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name); 1800 1801 if (table) 1802 __ip6t_unregister_table(net, table); 1803 } 1804 1805 /* Returns 1 if the type and code is matched by the range, 0 otherwise */ 1806 static inline bool 1807 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, 1808 u_int8_t type, u_int8_t code, 1809 bool invert) 1810 { 1811 return (type == test_type && code >= min_code && code <= max_code) 1812 ^ invert; 1813 } 1814 1815 static bool 1816 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par) 1817 { 1818 const struct icmp6hdr *ic; 1819 struct icmp6hdr _icmph; 1820 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1821 1822 /* Must not be a fragment. */ 1823 if (par->fragoff != 0) 1824 return false; 1825 1826 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); 1827 if (ic == NULL) { 1828 /* We've been asked to examine this packet, and we 1829 * can't. Hence, no choice but to drop. 1830 */ 1831 par->hotdrop = true; 1832 return false; 1833 } 1834 1835 return icmp6_type_code_match(icmpinfo->type, 1836 icmpinfo->code[0], 1837 icmpinfo->code[1], 1838 ic->icmp6_type, ic->icmp6_code, 1839 !!(icmpinfo->invflags&IP6T_ICMP_INV)); 1840 } 1841 1842 /* Called when user tries to insert an entry of this type. */ 1843 static int icmp6_checkentry(const struct xt_mtchk_param *par) 1844 { 1845 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1846 1847 /* Must specify no unknown invflags */ 1848 return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0; 1849 } 1850 1851 /* The built-in targets: standard (NULL) and error. */ 1852 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1853 { 1854 .name = XT_STANDARD_TARGET, 1855 .targetsize = sizeof(int), 1856 .family = NFPROTO_IPV6, 1857 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1858 .compatsize = sizeof(compat_int_t), 1859 .compat_from_user = compat_standard_from_user, 1860 .compat_to_user = compat_standard_to_user, 1861 #endif 1862 }, 1863 { 1864 .name = XT_ERROR_TARGET, 1865 .target = ip6t_error, 1866 .targetsize = XT_FUNCTION_MAXNAMELEN, 1867 .family = NFPROTO_IPV6, 1868 }, 1869 }; 1870 1871 static struct nf_sockopt_ops ip6t_sockopts = { 1872 .pf = PF_INET6, 1873 .set_optmin = IP6T_BASE_CTL, 1874 .set_optmax = IP6T_SO_SET_MAX+1, 1875 .set = do_ip6t_set_ctl, 1876 .get_optmin = IP6T_BASE_CTL, 1877 .get_optmax = IP6T_SO_GET_MAX+1, 1878 .get = do_ip6t_get_ctl, 1879 .owner = THIS_MODULE, 1880 }; 1881 1882 static struct xt_match ip6t_builtin_mt[] __read_mostly = { 1883 { 1884 .name = "icmp6", 1885 .match = icmp6_match, 1886 .matchsize = sizeof(struct ip6t_icmp), 1887 .checkentry = icmp6_checkentry, 1888 .proto = IPPROTO_ICMPV6, 1889 .family = NFPROTO_IPV6, 1890 .me = THIS_MODULE, 1891 }, 1892 }; 1893 1894 static int __net_init ip6_tables_net_init(struct net *net) 1895 { 1896 return xt_proto_init(net, NFPROTO_IPV6); 1897 } 1898 1899 static void __net_exit ip6_tables_net_exit(struct net *net) 1900 { 1901 xt_proto_fini(net, NFPROTO_IPV6); 1902 } 1903 1904 static struct pernet_operations ip6_tables_net_ops = { 1905 .init = ip6_tables_net_init, 1906 .exit = ip6_tables_net_exit, 1907 }; 1908 1909 static int __init ip6_tables_init(void) 1910 { 1911 int ret; 1912 1913 ret = register_pernet_subsys(&ip6_tables_net_ops); 1914 if (ret < 0) 1915 goto err1; 1916 1917 /* No one else will be downing sem now, so we won't sleep */ 1918 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1919 if (ret < 0) 1920 goto err2; 1921 ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1922 if (ret < 0) 1923 goto err4; 1924 1925 /* Register setsockopt */ 1926 ret = nf_register_sockopt(&ip6t_sockopts); 1927 if (ret < 0) 1928 goto err5; 1929 1930 return 0; 1931 1932 err5: 1933 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1934 err4: 1935 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1936 err2: 1937 unregister_pernet_subsys(&ip6_tables_net_ops); 1938 err1: 1939 return ret; 1940 } 1941 1942 static void __exit ip6_tables_fini(void) 1943 { 1944 nf_unregister_sockopt(&ip6t_sockopts); 1945 1946 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1947 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1948 unregister_pernet_subsys(&ip6_tables_net_ops); 1949 } 1950 1951 EXPORT_SYMBOL(ip6t_register_table); 1952 EXPORT_SYMBOL(ip6t_unregister_table_pre_exit); 1953 EXPORT_SYMBOL(ip6t_unregister_table_exit); 1954 EXPORT_SYMBOL(ip6t_do_table); 1955 1956 module_init(ip6_tables_init); 1957 module_exit(ip6_tables_fini); 1958