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 int *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(struct sk_buff *skb, 251 const struct nf_hook_state *state, 252 struct xt_table *table) 253 { 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.hotdrop = false; 277 acpar.state = state; 278 279 WARN_ON(!(table->valid_hooks & (1 << hook))); 280 281 local_bh_disable(); 282 addend = xt_write_recseq_begin(); 283 private = rcu_access_pointer(table->private); 284 cpu = smp_processor_id(); 285 table_base = private->entries; 286 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 287 288 /* Switch to alternate jumpstack if we're being invoked via TEE. 289 * TEE issues XT_CONTINUE verdict on original skb so we must not 290 * clobber the jumpstack. 291 * 292 * For recursion via REJECT or SYNPROXY the stack will be clobbered 293 * but it is no problem since absolute verdict is issued by these. 294 */ 295 if (static_key_false(&xt_tee_enabled)) 296 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); 297 298 e = get_entry(table_base, private->hook_entry[hook]); 299 300 do { 301 const struct xt_entry_target *t; 302 const struct xt_entry_match *ematch; 303 struct xt_counters *counter; 304 305 WARN_ON(!e); 306 acpar.thoff = 0; 307 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 308 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 309 no_match: 310 e = ip6t_next_entry(e); 311 continue; 312 } 313 314 xt_ematch_foreach(ematch, e) { 315 acpar.match = ematch->u.kernel.match; 316 acpar.matchinfo = ematch->data; 317 if (!acpar.match->match(skb, &acpar)) 318 goto no_match; 319 } 320 321 counter = xt_get_this_cpu_counter(&e->counters); 322 ADD_COUNTER(*counter, skb->len, 1); 323 324 t = ip6t_get_target_c(e); 325 WARN_ON(!t->u.kernel.target); 326 327 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 328 /* The packet is traced: log it */ 329 if (unlikely(skb->nf_trace)) 330 trace_packet(state->net, skb, hook, state->in, 331 state->out, table->name, private, e); 332 #endif 333 /* Standard target? */ 334 if (!t->u.kernel.target->target) { 335 int v; 336 337 v = ((struct xt_standard_target *)t)->verdict; 338 if (v < 0) { 339 /* Pop from stack? */ 340 if (v != XT_RETURN) { 341 verdict = (unsigned int)(-v) - 1; 342 break; 343 } 344 if (stackidx == 0) 345 e = get_entry(table_base, 346 private->underflow[hook]); 347 else 348 e = ip6t_next_entry(jumpstack[--stackidx]); 349 continue; 350 } 351 if (table_base + v != ip6t_next_entry(e) && 352 !(e->ipv6.flags & IP6T_F_GOTO)) { 353 if (unlikely(stackidx >= private->stacksize)) { 354 verdict = NF_DROP; 355 break; 356 } 357 jumpstack[stackidx++] = e; 358 } 359 360 e = get_entry(table_base, v); 361 continue; 362 } 363 364 acpar.target = t->u.kernel.target; 365 acpar.targinfo = t->data; 366 367 verdict = t->u.kernel.target->target(skb, &acpar); 368 if (verdict == XT_CONTINUE) 369 e = ip6t_next_entry(e); 370 else 371 /* Verdict */ 372 break; 373 } while (!acpar.hotdrop); 374 375 xt_write_recseq_end(addend); 376 local_bh_enable(); 377 378 if (acpar.hotdrop) 379 return NF_DROP; 380 else return verdict; 381 } 382 383 /* Figures out from what hook each rule can be called: returns 0 if 384 there are loops. Puts hook bitmask in comefrom. */ 385 static int 386 mark_source_chains(const struct xt_table_info *newinfo, 387 unsigned int valid_hooks, void *entry0, 388 unsigned int *offsets) 389 { 390 unsigned int hook; 391 392 /* No recursion; use packet counter to save back ptrs (reset 393 to 0 as we leave), and comefrom to save source hook bitmask */ 394 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 395 unsigned int pos = newinfo->hook_entry[hook]; 396 struct ip6t_entry *e = entry0 + pos; 397 398 if (!(valid_hooks & (1 << hook))) 399 continue; 400 401 /* Set initial back pointer. */ 402 e->counters.pcnt = pos; 403 404 for (;;) { 405 const struct xt_standard_target *t 406 = (void *)ip6t_get_target_c(e); 407 int visited = e->comefrom & (1 << hook); 408 409 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 410 return 0; 411 412 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 413 414 /* Unconditional return/END. */ 415 if ((unconditional(e) && 416 (strcmp(t->target.u.user.name, 417 XT_STANDARD_TARGET) == 0) && 418 t->verdict < 0) || visited) { 419 unsigned int oldpos, size; 420 421 /* Return: backtrack through the last 422 big jump. */ 423 do { 424 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 425 oldpos = pos; 426 pos = e->counters.pcnt; 427 e->counters.pcnt = 0; 428 429 /* We're at the start. */ 430 if (pos == oldpos) 431 goto next; 432 433 e = entry0 + pos; 434 } while (oldpos == pos + e->next_offset); 435 436 /* Move along one */ 437 size = e->next_offset; 438 e = entry0 + pos + size; 439 if (pos + size >= newinfo->size) 440 return 0; 441 e->counters.pcnt = pos; 442 pos += size; 443 } else { 444 int newpos = t->verdict; 445 446 if (strcmp(t->target.u.user.name, 447 XT_STANDARD_TARGET) == 0 && 448 newpos >= 0) { 449 /* This a jump; chase it. */ 450 if (!xt_find_jump_offset(offsets, newpos, 451 newinfo->number)) 452 return 0; 453 } else { 454 /* ... this is a fallthru */ 455 newpos = pos + e->next_offset; 456 if (newpos >= newinfo->size) 457 return 0; 458 } 459 e = entry0 + newpos; 460 e->counters.pcnt = pos; 461 pos = newpos; 462 } 463 } 464 next: ; 465 } 466 return 1; 467 } 468 469 static void cleanup_match(struct xt_entry_match *m, struct net *net) 470 { 471 struct xt_mtdtor_param par; 472 473 par.net = net; 474 par.match = m->u.kernel.match; 475 par.matchinfo = m->data; 476 par.family = NFPROTO_IPV6; 477 if (par.match->destroy != NULL) 478 par.match->destroy(&par); 479 module_put(par.match->me); 480 } 481 482 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 483 { 484 const struct ip6t_ip6 *ipv6 = par->entryinfo; 485 486 par->match = m->u.kernel.match; 487 par->matchinfo = m->data; 488 489 return xt_check_match(par, m->u.match_size - sizeof(*m), 490 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 491 } 492 493 static int 494 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 495 { 496 struct xt_match *match; 497 int ret; 498 499 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 500 m->u.user.revision); 501 if (IS_ERR(match)) 502 return PTR_ERR(match); 503 504 m->u.kernel.match = match; 505 506 ret = check_match(m, par); 507 if (ret) 508 goto err; 509 510 return 0; 511 err: 512 module_put(m->u.kernel.match->me); 513 return ret; 514 } 515 516 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 517 { 518 struct xt_entry_target *t = ip6t_get_target(e); 519 struct xt_tgchk_param par = { 520 .net = net, 521 .table = name, 522 .entryinfo = e, 523 .target = t->u.kernel.target, 524 .targinfo = t->data, 525 .hook_mask = e->comefrom, 526 .family = NFPROTO_IPV6, 527 }; 528 529 return xt_check_target(&par, t->u.target_size - sizeof(*t), 530 e->ipv6.proto, 531 e->ipv6.invflags & IP6T_INV_PROTO); 532 } 533 534 static int 535 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 536 unsigned int size, 537 struct xt_percpu_counter_alloc_state *alloc_state) 538 { 539 struct xt_entry_target *t; 540 struct xt_target *target; 541 int ret; 542 unsigned int j; 543 struct xt_mtchk_param mtpar; 544 struct xt_entry_match *ematch; 545 546 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 547 return -ENOMEM; 548 549 j = 0; 550 memset(&mtpar, 0, sizeof(mtpar)); 551 mtpar.net = net; 552 mtpar.table = name; 553 mtpar.entryinfo = &e->ipv6; 554 mtpar.hook_mask = e->comefrom; 555 mtpar.family = NFPROTO_IPV6; 556 xt_ematch_foreach(ematch, e) { 557 ret = find_check_match(ematch, &mtpar); 558 if (ret != 0) 559 goto cleanup_matches; 560 ++j; 561 } 562 563 t = ip6t_get_target(e); 564 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 565 t->u.user.revision); 566 if (IS_ERR(target)) { 567 ret = PTR_ERR(target); 568 goto cleanup_matches; 569 } 570 t->u.kernel.target = target; 571 572 ret = check_target(e, net, name); 573 if (ret) 574 goto err; 575 return 0; 576 err: 577 module_put(t->u.kernel.target->me); 578 cleanup_matches: 579 xt_ematch_foreach(ematch, e) { 580 if (j-- == 0) 581 break; 582 cleanup_match(ematch, net); 583 } 584 585 xt_percpu_counter_free(&e->counters); 586 587 return ret; 588 } 589 590 static bool check_underflow(const struct ip6t_entry *e) 591 { 592 const struct xt_entry_target *t; 593 unsigned int verdict; 594 595 if (!unconditional(e)) 596 return false; 597 t = ip6t_get_target_c(e); 598 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 599 return false; 600 verdict = ((struct xt_standard_target *)t)->verdict; 601 verdict = -verdict - 1; 602 return verdict == NF_DROP || verdict == NF_ACCEPT; 603 } 604 605 static int 606 check_entry_size_and_hooks(struct ip6t_entry *e, 607 struct xt_table_info *newinfo, 608 const unsigned char *base, 609 const unsigned char *limit, 610 const unsigned int *hook_entries, 611 const unsigned int *underflows, 612 unsigned int valid_hooks) 613 { 614 unsigned int h; 615 int err; 616 617 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 618 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 619 (unsigned char *)e + e->next_offset > limit) 620 return -EINVAL; 621 622 if (e->next_offset 623 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 624 return -EINVAL; 625 626 if (!ip6_checkentry(&e->ipv6)) 627 return -EINVAL; 628 629 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 630 e->next_offset); 631 if (err) 632 return err; 633 634 /* Check hooks & underflows */ 635 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 636 if (!(valid_hooks & (1 << h))) 637 continue; 638 if ((unsigned char *)e - base == hook_entries[h]) 639 newinfo->hook_entry[h] = hook_entries[h]; 640 if ((unsigned char *)e - base == underflows[h]) { 641 if (!check_underflow(e)) 642 return -EINVAL; 643 644 newinfo->underflow[h] = underflows[h]; 645 } 646 } 647 648 /* Clear counters and comefrom */ 649 e->counters = ((struct xt_counters) { 0, 0 }); 650 e->comefrom = 0; 651 return 0; 652 } 653 654 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 655 { 656 struct xt_tgdtor_param par; 657 struct xt_entry_target *t; 658 struct xt_entry_match *ematch; 659 660 /* Cleanup all matches */ 661 xt_ematch_foreach(ematch, e) 662 cleanup_match(ematch, net); 663 t = ip6t_get_target(e); 664 665 par.net = net; 666 par.target = t->u.kernel.target; 667 par.targinfo = t->data; 668 par.family = NFPROTO_IPV6; 669 if (par.target->destroy != NULL) 670 par.target->destroy(&par); 671 module_put(par.target->me); 672 xt_percpu_counter_free(&e->counters); 673 } 674 675 /* Checks and translates the user-supplied table segment (held in 676 newinfo) */ 677 static int 678 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 679 const struct ip6t_replace *repl) 680 { 681 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 682 struct ip6t_entry *iter; 683 unsigned int *offsets; 684 unsigned int i; 685 int ret = 0; 686 687 newinfo->size = repl->size; 688 newinfo->number = repl->num_entries; 689 690 /* Init all hooks to impossible value. */ 691 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 692 newinfo->hook_entry[i] = 0xFFFFFFFF; 693 newinfo->underflow[i] = 0xFFFFFFFF; 694 } 695 696 offsets = xt_alloc_entry_offsets(newinfo->number); 697 if (!offsets) 698 return -ENOMEM; 699 i = 0; 700 /* Walk through entries, checking offsets. */ 701 xt_entry_foreach(iter, entry0, newinfo->size) { 702 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 703 entry0 + repl->size, 704 repl->hook_entry, 705 repl->underflow, 706 repl->valid_hooks); 707 if (ret != 0) 708 goto out_free; 709 if (i < repl->num_entries) 710 offsets[i] = (void *)iter - entry0; 711 ++i; 712 if (strcmp(ip6t_get_target(iter)->u.user.name, 713 XT_ERROR_TARGET) == 0) 714 ++newinfo->stacksize; 715 } 716 717 ret = -EINVAL; 718 if (i != repl->num_entries) 719 goto out_free; 720 721 ret = xt_check_table_hooks(newinfo, repl->valid_hooks); 722 if (ret) 723 goto out_free; 724 725 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 726 ret = -ELOOP; 727 goto out_free; 728 } 729 kvfree(offsets); 730 731 /* Finally, each sanity check must pass */ 732 i = 0; 733 xt_entry_foreach(iter, entry0, newinfo->size) { 734 ret = find_check_entry(iter, net, repl->name, repl->size, 735 &alloc_state); 736 if (ret != 0) 737 break; 738 ++i; 739 } 740 741 if (ret != 0) { 742 xt_entry_foreach(iter, entry0, newinfo->size) { 743 if (i-- == 0) 744 break; 745 cleanup_entry(iter, net); 746 } 747 return ret; 748 } 749 750 return ret; 751 out_free: 752 kvfree(offsets); 753 return ret; 754 } 755 756 static void 757 get_counters(const struct xt_table_info *t, 758 struct xt_counters counters[]) 759 { 760 struct ip6t_entry *iter; 761 unsigned int cpu; 762 unsigned int i; 763 764 for_each_possible_cpu(cpu) { 765 seqcount_t *s = &per_cpu(xt_recseq, cpu); 766 767 i = 0; 768 xt_entry_foreach(iter, t->entries, t->size) { 769 struct xt_counters *tmp; 770 u64 bcnt, pcnt; 771 unsigned int start; 772 773 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 774 do { 775 start = read_seqcount_begin(s); 776 bcnt = tmp->bcnt; 777 pcnt = tmp->pcnt; 778 } while (read_seqcount_retry(s, start)); 779 780 ADD_COUNTER(counters[i], bcnt, pcnt); 781 ++i; 782 cond_resched(); 783 } 784 } 785 } 786 787 static void get_old_counters(const struct xt_table_info *t, 788 struct xt_counters counters[]) 789 { 790 struct ip6t_entry *iter; 791 unsigned int cpu, i; 792 793 for_each_possible_cpu(cpu) { 794 i = 0; 795 xt_entry_foreach(iter, t->entries, t->size) { 796 const struct xt_counters *tmp; 797 798 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 799 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 800 ++i; 801 } 802 cond_resched(); 803 } 804 } 805 806 static struct xt_counters *alloc_counters(const struct xt_table *table) 807 { 808 unsigned int countersize; 809 struct xt_counters *counters; 810 const struct xt_table_info *private = xt_table_get_private_protected(table); 811 812 /* We need atomic snapshot of counters: rest doesn't change 813 (other than comefrom, which userspace doesn't care 814 about). */ 815 countersize = sizeof(struct xt_counters) * private->number; 816 counters = vzalloc(countersize); 817 818 if (counters == NULL) 819 return ERR_PTR(-ENOMEM); 820 821 get_counters(private, counters); 822 823 return counters; 824 } 825 826 static int 827 copy_entries_to_user(unsigned int total_size, 828 const struct xt_table *table, 829 void __user *userptr) 830 { 831 unsigned int off, num; 832 const struct ip6t_entry *e; 833 struct xt_counters *counters; 834 const struct xt_table_info *private = xt_table_get_private_protected(table); 835 int ret = 0; 836 const void *loc_cpu_entry; 837 838 counters = alloc_counters(table); 839 if (IS_ERR(counters)) 840 return PTR_ERR(counters); 841 842 loc_cpu_entry = private->entries; 843 844 /* FIXME: use iterator macros --RR */ 845 /* ... then go back and fix counters and names */ 846 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 847 unsigned int i; 848 const struct xt_entry_match *m; 849 const struct xt_entry_target *t; 850 851 e = loc_cpu_entry + off; 852 if (copy_to_user(userptr + off, e, sizeof(*e))) { 853 ret = -EFAULT; 854 goto free_counters; 855 } 856 if (copy_to_user(userptr + off 857 + offsetof(struct ip6t_entry, counters), 858 &counters[num], 859 sizeof(counters[num])) != 0) { 860 ret = -EFAULT; 861 goto free_counters; 862 } 863 864 for (i = sizeof(struct ip6t_entry); 865 i < e->target_offset; 866 i += m->u.match_size) { 867 m = (void *)e + i; 868 869 if (xt_match_to_user(m, userptr + off + i)) { 870 ret = -EFAULT; 871 goto free_counters; 872 } 873 } 874 875 t = ip6t_get_target_c(e); 876 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 877 ret = -EFAULT; 878 goto free_counters; 879 } 880 } 881 882 free_counters: 883 vfree(counters); 884 return ret; 885 } 886 887 #ifdef CONFIG_COMPAT 888 static void compat_standard_from_user(void *dst, const void *src) 889 { 890 int v = *(compat_int_t *)src; 891 892 if (v > 0) 893 v += xt_compat_calc_jump(AF_INET6, v); 894 memcpy(dst, &v, sizeof(v)); 895 } 896 897 static int compat_standard_to_user(void __user *dst, const void *src) 898 { 899 compat_int_t cv = *(int *)src; 900 901 if (cv > 0) 902 cv -= xt_compat_calc_jump(AF_INET6, cv); 903 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 904 } 905 906 static int compat_calc_entry(const struct ip6t_entry *e, 907 const struct xt_table_info *info, 908 const void *base, struct xt_table_info *newinfo) 909 { 910 const struct xt_entry_match *ematch; 911 const struct xt_entry_target *t; 912 unsigned int entry_offset; 913 int off, i, ret; 914 915 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 916 entry_offset = (void *)e - base; 917 xt_ematch_foreach(ematch, e) 918 off += xt_compat_match_offset(ematch->u.kernel.match); 919 t = ip6t_get_target_c(e); 920 off += xt_compat_target_offset(t->u.kernel.target); 921 newinfo->size -= off; 922 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 923 if (ret) 924 return ret; 925 926 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 927 if (info->hook_entry[i] && 928 (e < (struct ip6t_entry *)(base + info->hook_entry[i]))) 929 newinfo->hook_entry[i] -= off; 930 if (info->underflow[i] && 931 (e < (struct ip6t_entry *)(base + info->underflow[i]))) 932 newinfo->underflow[i] -= off; 933 } 934 return 0; 935 } 936 937 static int compat_table_info(const struct xt_table_info *info, 938 struct xt_table_info *newinfo) 939 { 940 struct ip6t_entry *iter; 941 const void *loc_cpu_entry; 942 int ret; 943 944 if (!newinfo || !info) 945 return -EINVAL; 946 947 /* we dont care about newinfo->entries */ 948 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 949 newinfo->initial_entries = 0; 950 loc_cpu_entry = info->entries; 951 ret = xt_compat_init_offsets(AF_INET6, info->number); 952 if (ret) 953 return ret; 954 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 955 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 956 if (ret != 0) 957 return ret; 958 } 959 return 0; 960 } 961 #endif 962 963 static int get_info(struct net *net, void __user *user, const int *len) 964 { 965 char name[XT_TABLE_MAXNAMELEN]; 966 struct xt_table *t; 967 int ret; 968 969 if (*len != sizeof(struct ip6t_getinfo)) 970 return -EINVAL; 971 972 if (copy_from_user(name, user, sizeof(name)) != 0) 973 return -EFAULT; 974 975 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 976 #ifdef CONFIG_COMPAT 977 if (in_compat_syscall()) 978 xt_compat_lock(AF_INET6); 979 #endif 980 t = xt_request_find_table_lock(net, AF_INET6, name); 981 if (!IS_ERR(t)) { 982 struct ip6t_getinfo info; 983 const struct xt_table_info *private = xt_table_get_private_protected(t); 984 #ifdef CONFIG_COMPAT 985 struct xt_table_info tmp; 986 987 if (in_compat_syscall()) { 988 ret = compat_table_info(private, &tmp); 989 xt_compat_flush_offsets(AF_INET6); 990 private = &tmp; 991 } 992 #endif 993 memset(&info, 0, sizeof(info)); 994 info.valid_hooks = t->valid_hooks; 995 memcpy(info.hook_entry, private->hook_entry, 996 sizeof(info.hook_entry)); 997 memcpy(info.underflow, private->underflow, 998 sizeof(info.underflow)); 999 info.num_entries = private->number; 1000 info.size = private->size; 1001 strcpy(info.name, name); 1002 1003 if (copy_to_user(user, &info, *len) != 0) 1004 ret = -EFAULT; 1005 else 1006 ret = 0; 1007 1008 xt_table_unlock(t); 1009 module_put(t->me); 1010 } else 1011 ret = PTR_ERR(t); 1012 #ifdef CONFIG_COMPAT 1013 if (in_compat_syscall()) 1014 xt_compat_unlock(AF_INET6); 1015 #endif 1016 return ret; 1017 } 1018 1019 static int 1020 get_entries(struct net *net, struct ip6t_get_entries __user *uptr, 1021 const int *len) 1022 { 1023 int ret; 1024 struct ip6t_get_entries get; 1025 struct xt_table *t; 1026 1027 if (*len < sizeof(get)) 1028 return -EINVAL; 1029 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1030 return -EFAULT; 1031 if (*len != sizeof(struct ip6t_get_entries) + get.size) 1032 return -EINVAL; 1033 1034 get.name[sizeof(get.name) - 1] = '\0'; 1035 1036 t = xt_find_table_lock(net, AF_INET6, get.name); 1037 if (!IS_ERR(t)) { 1038 struct xt_table_info *private = xt_table_get_private_protected(t); 1039 if (get.size == private->size) 1040 ret = copy_entries_to_user(private->size, 1041 t, uptr->entrytable); 1042 else 1043 ret = -EAGAIN; 1044 1045 module_put(t->me); 1046 xt_table_unlock(t); 1047 } else 1048 ret = PTR_ERR(t); 1049 1050 return ret; 1051 } 1052 1053 static int 1054 __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1055 struct xt_table_info *newinfo, unsigned int num_counters, 1056 void __user *counters_ptr) 1057 { 1058 int ret; 1059 struct xt_table *t; 1060 struct xt_table_info *oldinfo; 1061 struct xt_counters *counters; 1062 struct ip6t_entry *iter; 1063 1064 ret = 0; 1065 counters = xt_counters_alloc(num_counters); 1066 if (!counters) { 1067 ret = -ENOMEM; 1068 goto out; 1069 } 1070 1071 t = xt_request_find_table_lock(net, AF_INET6, name); 1072 if (IS_ERR(t)) { 1073 ret = PTR_ERR(t); 1074 goto free_newinfo_counters_untrans; 1075 } 1076 1077 /* You lied! */ 1078 if (valid_hooks != t->valid_hooks) { 1079 ret = -EINVAL; 1080 goto put_module; 1081 } 1082 1083 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1084 if (!oldinfo) 1085 goto put_module; 1086 1087 /* Update module usage count based on number of rules */ 1088 if ((oldinfo->number > oldinfo->initial_entries) || 1089 (newinfo->number <= oldinfo->initial_entries)) 1090 module_put(t->me); 1091 if ((oldinfo->number > oldinfo->initial_entries) && 1092 (newinfo->number <= oldinfo->initial_entries)) 1093 module_put(t->me); 1094 1095 xt_table_unlock(t); 1096 1097 get_old_counters(oldinfo, counters); 1098 1099 /* Decrease module usage counts and free resource */ 1100 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1101 cleanup_entry(iter, net); 1102 1103 xt_free_table_info(oldinfo); 1104 if (copy_to_user(counters_ptr, counters, 1105 sizeof(struct xt_counters) * num_counters) != 0) { 1106 /* Silent error, can't fail, new table is already in place */ 1107 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1108 } 1109 vfree(counters); 1110 return ret; 1111 1112 put_module: 1113 module_put(t->me); 1114 xt_table_unlock(t); 1115 free_newinfo_counters_untrans: 1116 vfree(counters); 1117 out: 1118 return ret; 1119 } 1120 1121 static int 1122 do_replace(struct net *net, sockptr_t arg, unsigned int len) 1123 { 1124 int ret; 1125 struct ip6t_replace tmp; 1126 struct xt_table_info *newinfo; 1127 void *loc_cpu_entry; 1128 struct ip6t_entry *iter; 1129 1130 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1131 return -EFAULT; 1132 1133 /* overflow check */ 1134 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1135 return -ENOMEM; 1136 if (tmp.num_counters == 0) 1137 return -EINVAL; 1138 1139 tmp.name[sizeof(tmp.name)-1] = 0; 1140 1141 newinfo = xt_alloc_table_info(tmp.size); 1142 if (!newinfo) 1143 return -ENOMEM; 1144 1145 loc_cpu_entry = newinfo->entries; 1146 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1147 tmp.size) != 0) { 1148 ret = -EFAULT; 1149 goto free_newinfo; 1150 } 1151 1152 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1153 if (ret != 0) 1154 goto free_newinfo; 1155 1156 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1157 tmp.num_counters, tmp.counters); 1158 if (ret) 1159 goto free_newinfo_untrans; 1160 return 0; 1161 1162 free_newinfo_untrans: 1163 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1164 cleanup_entry(iter, net); 1165 free_newinfo: 1166 xt_free_table_info(newinfo); 1167 return ret; 1168 } 1169 1170 static int 1171 do_add_counters(struct net *net, sockptr_t arg, unsigned int len) 1172 { 1173 unsigned int i; 1174 struct xt_counters_info tmp; 1175 struct xt_counters *paddc; 1176 struct xt_table *t; 1177 const struct xt_table_info *private; 1178 int ret = 0; 1179 struct ip6t_entry *iter; 1180 unsigned int addend; 1181 1182 paddc = xt_copy_counters(arg, len, &tmp); 1183 if (IS_ERR(paddc)) 1184 return PTR_ERR(paddc); 1185 t = xt_find_table_lock(net, AF_INET6, tmp.name); 1186 if (IS_ERR(t)) { 1187 ret = PTR_ERR(t); 1188 goto free; 1189 } 1190 1191 local_bh_disable(); 1192 private = xt_table_get_private_protected(t); 1193 if (private->number != tmp.num_counters) { 1194 ret = -EINVAL; 1195 goto unlock_up_free; 1196 } 1197 1198 i = 0; 1199 addend = xt_write_recseq_begin(); 1200 xt_entry_foreach(iter, private->entries, private->size) { 1201 struct xt_counters *tmp; 1202 1203 tmp = xt_get_this_cpu_counter(&iter->counters); 1204 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); 1205 ++i; 1206 } 1207 xt_write_recseq_end(addend); 1208 unlock_up_free: 1209 local_bh_enable(); 1210 xt_table_unlock(t); 1211 module_put(t->me); 1212 free: 1213 vfree(paddc); 1214 1215 return ret; 1216 } 1217 1218 #ifdef CONFIG_COMPAT 1219 struct compat_ip6t_replace { 1220 char name[XT_TABLE_MAXNAMELEN]; 1221 u32 valid_hooks; 1222 u32 num_entries; 1223 u32 size; 1224 u32 hook_entry[NF_INET_NUMHOOKS]; 1225 u32 underflow[NF_INET_NUMHOOKS]; 1226 u32 num_counters; 1227 compat_uptr_t counters; /* struct xt_counters * */ 1228 struct compat_ip6t_entry entries[]; 1229 }; 1230 1231 static int 1232 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr, 1233 unsigned int *size, struct xt_counters *counters, 1234 unsigned int i) 1235 { 1236 struct xt_entry_target *t; 1237 struct compat_ip6t_entry __user *ce; 1238 u_int16_t target_offset, next_offset; 1239 compat_uint_t origsize; 1240 const struct xt_entry_match *ematch; 1241 int ret = 0; 1242 1243 origsize = *size; 1244 ce = *dstptr; 1245 if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 || 1246 copy_to_user(&ce->counters, &counters[i], 1247 sizeof(counters[i])) != 0) 1248 return -EFAULT; 1249 1250 *dstptr += sizeof(struct compat_ip6t_entry); 1251 *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1252 1253 xt_ematch_foreach(ematch, e) { 1254 ret = xt_compat_match_to_user(ematch, dstptr, size); 1255 if (ret != 0) 1256 return ret; 1257 } 1258 target_offset = e->target_offset - (origsize - *size); 1259 t = ip6t_get_target(e); 1260 ret = xt_compat_target_to_user(t, dstptr, size); 1261 if (ret) 1262 return ret; 1263 next_offset = e->next_offset - (origsize - *size); 1264 if (put_user(target_offset, &ce->target_offset) != 0 || 1265 put_user(next_offset, &ce->next_offset) != 0) 1266 return -EFAULT; 1267 return 0; 1268 } 1269 1270 static int 1271 compat_find_calc_match(struct xt_entry_match *m, 1272 const struct ip6t_ip6 *ipv6, 1273 int *size) 1274 { 1275 struct xt_match *match; 1276 1277 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 1278 m->u.user.revision); 1279 if (IS_ERR(match)) 1280 return PTR_ERR(match); 1281 1282 m->u.kernel.match = match; 1283 *size += xt_compat_match_offset(match); 1284 return 0; 1285 } 1286 1287 static void compat_release_entry(struct compat_ip6t_entry *e) 1288 { 1289 struct xt_entry_target *t; 1290 struct xt_entry_match *ematch; 1291 1292 /* Cleanup all matches */ 1293 xt_ematch_foreach(ematch, e) 1294 module_put(ematch->u.kernel.match->me); 1295 t = compat_ip6t_get_target(e); 1296 module_put(t->u.kernel.target->me); 1297 } 1298 1299 static int 1300 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, 1301 struct xt_table_info *newinfo, 1302 unsigned int *size, 1303 const unsigned char *base, 1304 const unsigned char *limit) 1305 { 1306 struct xt_entry_match *ematch; 1307 struct xt_entry_target *t; 1308 struct xt_target *target; 1309 unsigned int entry_offset; 1310 unsigned int j; 1311 int ret, off; 1312 1313 if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 || 1314 (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit || 1315 (unsigned char *)e + e->next_offset > limit) 1316 return -EINVAL; 1317 1318 if (e->next_offset < sizeof(struct compat_ip6t_entry) + 1319 sizeof(struct compat_xt_entry_target)) 1320 return -EINVAL; 1321 1322 if (!ip6_checkentry(&e->ipv6)) 1323 return -EINVAL; 1324 1325 ret = xt_compat_check_entry_offsets(e, e->elems, 1326 e->target_offset, e->next_offset); 1327 if (ret) 1328 return ret; 1329 1330 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1331 entry_offset = (void *)e - (void *)base; 1332 j = 0; 1333 xt_ematch_foreach(ematch, e) { 1334 ret = compat_find_calc_match(ematch, &e->ipv6, &off); 1335 if (ret != 0) 1336 goto release_matches; 1337 ++j; 1338 } 1339 1340 t = compat_ip6t_get_target(e); 1341 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 1342 t->u.user.revision); 1343 if (IS_ERR(target)) { 1344 ret = PTR_ERR(target); 1345 goto release_matches; 1346 } 1347 t->u.kernel.target = target; 1348 1349 off += xt_compat_target_offset(target); 1350 *size += off; 1351 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 1352 if (ret) 1353 goto out; 1354 1355 return 0; 1356 1357 out: 1358 module_put(t->u.kernel.target->me); 1359 release_matches: 1360 xt_ematch_foreach(ematch, e) { 1361 if (j-- == 0) 1362 break; 1363 module_put(ematch->u.kernel.match->me); 1364 } 1365 return ret; 1366 } 1367 1368 static void 1369 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, 1370 unsigned int *size, 1371 struct xt_table_info *newinfo, unsigned char *base) 1372 { 1373 struct xt_entry_target *t; 1374 struct ip6t_entry *de; 1375 unsigned int origsize; 1376 int h; 1377 struct xt_entry_match *ematch; 1378 1379 origsize = *size; 1380 de = *dstptr; 1381 memcpy(de, e, sizeof(struct ip6t_entry)); 1382 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1383 1384 *dstptr += sizeof(struct ip6t_entry); 1385 *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1386 1387 xt_ematch_foreach(ematch, e) 1388 xt_compat_match_from_user(ematch, dstptr, size); 1389 1390 de->target_offset = e->target_offset - (origsize - *size); 1391 t = compat_ip6t_get_target(e); 1392 xt_compat_target_from_user(t, dstptr, size); 1393 1394 de->next_offset = e->next_offset - (origsize - *size); 1395 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 1396 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1397 newinfo->hook_entry[h] -= origsize - *size; 1398 if ((unsigned char *)de - base < newinfo->underflow[h]) 1399 newinfo->underflow[h] -= origsize - *size; 1400 } 1401 } 1402 1403 static int 1404 translate_compat_table(struct net *net, 1405 struct xt_table_info **pinfo, 1406 void **pentry0, 1407 const struct compat_ip6t_replace *compatr) 1408 { 1409 unsigned int i, j; 1410 struct xt_table_info *newinfo, *info; 1411 void *pos, *entry0, *entry1; 1412 struct compat_ip6t_entry *iter0; 1413 struct ip6t_replace repl; 1414 unsigned int size; 1415 int ret; 1416 1417 info = *pinfo; 1418 entry0 = *pentry0; 1419 size = compatr->size; 1420 info->number = compatr->num_entries; 1421 1422 j = 0; 1423 xt_compat_lock(AF_INET6); 1424 ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries); 1425 if (ret) 1426 goto out_unlock; 1427 /* Walk through entries, checking offsets. */ 1428 xt_entry_foreach(iter0, entry0, compatr->size) { 1429 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1430 entry0, 1431 entry0 + compatr->size); 1432 if (ret != 0) 1433 goto out_unlock; 1434 ++j; 1435 } 1436 1437 ret = -EINVAL; 1438 if (j != compatr->num_entries) 1439 goto out_unlock; 1440 1441 ret = -ENOMEM; 1442 newinfo = xt_alloc_table_info(size); 1443 if (!newinfo) 1444 goto out_unlock; 1445 1446 newinfo->number = compatr->num_entries; 1447 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1448 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1449 newinfo->underflow[i] = compatr->underflow[i]; 1450 } 1451 entry1 = newinfo->entries; 1452 pos = entry1; 1453 size = compatr->size; 1454 xt_entry_foreach(iter0, entry0, compatr->size) 1455 compat_copy_entry_from_user(iter0, &pos, &size, 1456 newinfo, entry1); 1457 1458 /* all module references in entry0 are now gone. */ 1459 xt_compat_flush_offsets(AF_INET6); 1460 xt_compat_unlock(AF_INET6); 1461 1462 memcpy(&repl, compatr, sizeof(*compatr)); 1463 1464 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1465 repl.hook_entry[i] = newinfo->hook_entry[i]; 1466 repl.underflow[i] = newinfo->underflow[i]; 1467 } 1468 1469 repl.num_counters = 0; 1470 repl.counters = NULL; 1471 repl.size = newinfo->size; 1472 ret = translate_table(net, newinfo, entry1, &repl); 1473 if (ret) 1474 goto free_newinfo; 1475 1476 *pinfo = newinfo; 1477 *pentry0 = entry1; 1478 xt_free_table_info(info); 1479 return 0; 1480 1481 free_newinfo: 1482 xt_free_table_info(newinfo); 1483 return ret; 1484 out_unlock: 1485 xt_compat_flush_offsets(AF_INET6); 1486 xt_compat_unlock(AF_INET6); 1487 xt_entry_foreach(iter0, entry0, compatr->size) { 1488 if (j-- == 0) 1489 break; 1490 compat_release_entry(iter0); 1491 } 1492 return ret; 1493 } 1494 1495 static int 1496 compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) 1497 { 1498 int ret; 1499 struct compat_ip6t_replace tmp; 1500 struct xt_table_info *newinfo; 1501 void *loc_cpu_entry; 1502 struct ip6t_entry *iter; 1503 1504 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1505 return -EFAULT; 1506 1507 /* overflow check */ 1508 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1509 return -ENOMEM; 1510 if (tmp.num_counters == 0) 1511 return -EINVAL; 1512 1513 tmp.name[sizeof(tmp.name)-1] = 0; 1514 1515 newinfo = xt_alloc_table_info(tmp.size); 1516 if (!newinfo) 1517 return -ENOMEM; 1518 1519 loc_cpu_entry = newinfo->entries; 1520 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1521 tmp.size) != 0) { 1522 ret = -EFAULT; 1523 goto free_newinfo; 1524 } 1525 1526 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1527 if (ret != 0) 1528 goto free_newinfo; 1529 1530 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1531 tmp.num_counters, compat_ptr(tmp.counters)); 1532 if (ret) 1533 goto free_newinfo_untrans; 1534 return 0; 1535 1536 free_newinfo_untrans: 1537 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1538 cleanup_entry(iter, net); 1539 free_newinfo: 1540 xt_free_table_info(newinfo); 1541 return ret; 1542 } 1543 1544 struct compat_ip6t_get_entries { 1545 char name[XT_TABLE_MAXNAMELEN]; 1546 compat_uint_t size; 1547 struct compat_ip6t_entry entrytable[]; 1548 }; 1549 1550 static int 1551 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1552 void __user *userptr) 1553 { 1554 struct xt_counters *counters; 1555 const struct xt_table_info *private = xt_table_get_private_protected(table); 1556 void __user *pos; 1557 unsigned int size; 1558 int ret = 0; 1559 unsigned int i = 0; 1560 struct ip6t_entry *iter; 1561 1562 counters = alloc_counters(table); 1563 if (IS_ERR(counters)) 1564 return PTR_ERR(counters); 1565 1566 pos = userptr; 1567 size = total_size; 1568 xt_entry_foreach(iter, private->entries, total_size) { 1569 ret = compat_copy_entry_to_user(iter, &pos, 1570 &size, counters, i++); 1571 if (ret != 0) 1572 break; 1573 } 1574 1575 vfree(counters); 1576 return ret; 1577 } 1578 1579 static int 1580 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1581 int *len) 1582 { 1583 int ret; 1584 struct compat_ip6t_get_entries get; 1585 struct xt_table *t; 1586 1587 if (*len < sizeof(get)) 1588 return -EINVAL; 1589 1590 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1591 return -EFAULT; 1592 1593 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1594 return -EINVAL; 1595 1596 get.name[sizeof(get.name) - 1] = '\0'; 1597 1598 xt_compat_lock(AF_INET6); 1599 t = xt_find_table_lock(net, AF_INET6, get.name); 1600 if (!IS_ERR(t)) { 1601 const struct xt_table_info *private = xt_table_get_private_protected(t); 1602 struct xt_table_info info; 1603 ret = compat_table_info(private, &info); 1604 if (!ret && get.size == info.size) 1605 ret = compat_copy_entries_to_user(private->size, 1606 t, uptr->entrytable); 1607 else if (!ret) 1608 ret = -EAGAIN; 1609 1610 xt_compat_flush_offsets(AF_INET6); 1611 module_put(t->me); 1612 xt_table_unlock(t); 1613 } else 1614 ret = PTR_ERR(t); 1615 1616 xt_compat_unlock(AF_INET6); 1617 return ret; 1618 } 1619 #endif 1620 1621 static int 1622 do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len) 1623 { 1624 int ret; 1625 1626 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1627 return -EPERM; 1628 1629 switch (cmd) { 1630 case IP6T_SO_SET_REPLACE: 1631 #ifdef CONFIG_COMPAT 1632 if (in_compat_syscall()) 1633 ret = compat_do_replace(sock_net(sk), arg, len); 1634 else 1635 #endif 1636 ret = do_replace(sock_net(sk), arg, len); 1637 break; 1638 1639 case IP6T_SO_SET_ADD_COUNTERS: 1640 ret = do_add_counters(sock_net(sk), arg, len); 1641 break; 1642 1643 default: 1644 ret = -EINVAL; 1645 } 1646 1647 return ret; 1648 } 1649 1650 static int 1651 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1652 { 1653 int ret; 1654 1655 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1656 return -EPERM; 1657 1658 switch (cmd) { 1659 case IP6T_SO_GET_INFO: 1660 ret = get_info(sock_net(sk), user, len); 1661 break; 1662 1663 case IP6T_SO_GET_ENTRIES: 1664 #ifdef CONFIG_COMPAT 1665 if (in_compat_syscall()) 1666 ret = compat_get_entries(sock_net(sk), user, len); 1667 else 1668 #endif 1669 ret = get_entries(sock_net(sk), user, len); 1670 break; 1671 1672 case IP6T_SO_GET_REVISION_MATCH: 1673 case IP6T_SO_GET_REVISION_TARGET: { 1674 struct xt_get_revision rev; 1675 int target; 1676 1677 if (*len != sizeof(rev)) { 1678 ret = -EINVAL; 1679 break; 1680 } 1681 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1682 ret = -EFAULT; 1683 break; 1684 } 1685 rev.name[sizeof(rev.name)-1] = 0; 1686 1687 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1688 target = 1; 1689 else 1690 target = 0; 1691 1692 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1693 rev.revision, 1694 target, &ret), 1695 "ip6t_%s", rev.name); 1696 break; 1697 } 1698 1699 default: 1700 ret = -EINVAL; 1701 } 1702 1703 return ret; 1704 } 1705 1706 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1707 { 1708 struct xt_table_info *private; 1709 void *loc_cpu_entry; 1710 struct module *table_owner = table->me; 1711 struct ip6t_entry *iter; 1712 1713 private = xt_unregister_table(table); 1714 1715 /* Decrease module usage counts and free resources */ 1716 loc_cpu_entry = private->entries; 1717 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1718 cleanup_entry(iter, net); 1719 if (private->number > private->initial_entries) 1720 module_put(table_owner); 1721 xt_free_table_info(private); 1722 } 1723 1724 int ip6t_register_table(struct net *net, const struct xt_table *table, 1725 const struct ip6t_replace *repl, 1726 const struct nf_hook_ops *ops, 1727 struct xt_table **res) 1728 { 1729 int ret; 1730 struct xt_table_info *newinfo; 1731 struct xt_table_info bootstrap = {0}; 1732 void *loc_cpu_entry; 1733 struct xt_table *new_table; 1734 1735 newinfo = xt_alloc_table_info(repl->size); 1736 if (!newinfo) 1737 return -ENOMEM; 1738 1739 loc_cpu_entry = newinfo->entries; 1740 memcpy(loc_cpu_entry, repl->entries, repl->size); 1741 1742 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1743 if (ret != 0) 1744 goto out_free; 1745 1746 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1747 if (IS_ERR(new_table)) { 1748 ret = PTR_ERR(new_table); 1749 goto out_free; 1750 } 1751 1752 /* set res now, will see skbs right after nf_register_net_hooks */ 1753 WRITE_ONCE(*res, new_table); 1754 if (!ops) 1755 return 0; 1756 1757 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); 1758 if (ret != 0) { 1759 __ip6t_unregister_table(net, new_table); 1760 *res = NULL; 1761 } 1762 1763 return ret; 1764 1765 out_free: 1766 xt_free_table_info(newinfo); 1767 return ret; 1768 } 1769 1770 void ip6t_unregister_table_pre_exit(struct net *net, struct xt_table *table, 1771 const struct nf_hook_ops *ops) 1772 { 1773 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); 1774 } 1775 1776 void ip6t_unregister_table_exit(struct net *net, struct xt_table *table) 1777 { 1778 __ip6t_unregister_table(net, table); 1779 } 1780 1781 void ip6t_unregister_table(struct net *net, struct xt_table *table, 1782 const struct nf_hook_ops *ops) 1783 { 1784 if (ops) 1785 ip6t_unregister_table_pre_exit(net, table, ops); 1786 __ip6t_unregister_table(net, table); 1787 } 1788 1789 /* Returns 1 if the type and code is matched by the range, 0 otherwise */ 1790 static inline bool 1791 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, 1792 u_int8_t type, u_int8_t code, 1793 bool invert) 1794 { 1795 return (type == test_type && code >= min_code && code <= max_code) 1796 ^ invert; 1797 } 1798 1799 static bool 1800 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par) 1801 { 1802 const struct icmp6hdr *ic; 1803 struct icmp6hdr _icmph; 1804 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1805 1806 /* Must not be a fragment. */ 1807 if (par->fragoff != 0) 1808 return false; 1809 1810 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); 1811 if (ic == NULL) { 1812 /* We've been asked to examine this packet, and we 1813 * can't. Hence, no choice but to drop. 1814 */ 1815 par->hotdrop = true; 1816 return false; 1817 } 1818 1819 return icmp6_type_code_match(icmpinfo->type, 1820 icmpinfo->code[0], 1821 icmpinfo->code[1], 1822 ic->icmp6_type, ic->icmp6_code, 1823 !!(icmpinfo->invflags&IP6T_ICMP_INV)); 1824 } 1825 1826 /* Called when user tries to insert an entry of this type. */ 1827 static int icmp6_checkentry(const struct xt_mtchk_param *par) 1828 { 1829 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1830 1831 /* Must specify no unknown invflags */ 1832 return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0; 1833 } 1834 1835 /* The built-in targets: standard (NULL) and error. */ 1836 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1837 { 1838 .name = XT_STANDARD_TARGET, 1839 .targetsize = sizeof(int), 1840 .family = NFPROTO_IPV6, 1841 #ifdef CONFIG_COMPAT 1842 .compatsize = sizeof(compat_int_t), 1843 .compat_from_user = compat_standard_from_user, 1844 .compat_to_user = compat_standard_to_user, 1845 #endif 1846 }, 1847 { 1848 .name = XT_ERROR_TARGET, 1849 .target = ip6t_error, 1850 .targetsize = XT_FUNCTION_MAXNAMELEN, 1851 .family = NFPROTO_IPV6, 1852 }, 1853 }; 1854 1855 static struct nf_sockopt_ops ip6t_sockopts = { 1856 .pf = PF_INET6, 1857 .set_optmin = IP6T_BASE_CTL, 1858 .set_optmax = IP6T_SO_SET_MAX+1, 1859 .set = do_ip6t_set_ctl, 1860 .get_optmin = IP6T_BASE_CTL, 1861 .get_optmax = IP6T_SO_GET_MAX+1, 1862 .get = do_ip6t_get_ctl, 1863 .owner = THIS_MODULE, 1864 }; 1865 1866 static struct xt_match ip6t_builtin_mt[] __read_mostly = { 1867 { 1868 .name = "icmp6", 1869 .match = icmp6_match, 1870 .matchsize = sizeof(struct ip6t_icmp), 1871 .checkentry = icmp6_checkentry, 1872 .proto = IPPROTO_ICMPV6, 1873 .family = NFPROTO_IPV6, 1874 .me = THIS_MODULE, 1875 }, 1876 }; 1877 1878 static int __net_init ip6_tables_net_init(struct net *net) 1879 { 1880 return xt_proto_init(net, NFPROTO_IPV6); 1881 } 1882 1883 static void __net_exit ip6_tables_net_exit(struct net *net) 1884 { 1885 xt_proto_fini(net, NFPROTO_IPV6); 1886 } 1887 1888 static struct pernet_operations ip6_tables_net_ops = { 1889 .init = ip6_tables_net_init, 1890 .exit = ip6_tables_net_exit, 1891 }; 1892 1893 static int __init ip6_tables_init(void) 1894 { 1895 int ret; 1896 1897 ret = register_pernet_subsys(&ip6_tables_net_ops); 1898 if (ret < 0) 1899 goto err1; 1900 1901 /* No one else will be downing sem now, so we won't sleep */ 1902 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1903 if (ret < 0) 1904 goto err2; 1905 ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1906 if (ret < 0) 1907 goto err4; 1908 1909 /* Register setsockopt */ 1910 ret = nf_register_sockopt(&ip6t_sockopts); 1911 if (ret < 0) 1912 goto err5; 1913 1914 return 0; 1915 1916 err5: 1917 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1918 err4: 1919 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1920 err2: 1921 unregister_pernet_subsys(&ip6_tables_net_ops); 1922 err1: 1923 return ret; 1924 } 1925 1926 static void __exit ip6_tables_fini(void) 1927 { 1928 nf_unregister_sockopt(&ip6t_sockopts); 1929 1930 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1931 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1932 unregister_pernet_subsys(&ip6_tables_net_ops); 1933 } 1934 1935 EXPORT_SYMBOL(ip6t_register_table); 1936 EXPORT_SYMBOL(ip6t_unregister_table); 1937 EXPORT_SYMBOL(ip6t_unregister_table_pre_exit); 1938 EXPORT_SYMBOL(ip6t_unregister_table_exit); 1939 EXPORT_SYMBOL(ip6t_do_table); 1940 1941 module_init(ip6_tables_init); 1942 module_exit(ip6_tables_fini); 1943