1 /* 2 * Packet matching code. 3 * 4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 5 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> 6 * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/kernel.h> 16 #include <linux/capability.h> 17 #include <linux/in.h> 18 #include <linux/skbuff.h> 19 #include <linux/kmod.h> 20 #include <linux/vmalloc.h> 21 #include <linux/netdevice.h> 22 #include <linux/module.h> 23 #include <linux/poison.h> 24 #include <linux/icmpv6.h> 25 #include <net/ipv6.h> 26 #include <net/compat.h> 27 #include <linux/uaccess.h> 28 #include <linux/mutex.h> 29 #include <linux/proc_fs.h> 30 #include <linux/err.h> 31 #include <linux/cpumask.h> 32 33 #include <linux/netfilter_ipv6/ip6_tables.h> 34 #include <linux/netfilter/x_tables.h> 35 #include <net/netfilter/nf_log.h> 36 #include "../../netfilter/xt_repldata.h" 37 38 MODULE_LICENSE("GPL"); 39 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 40 MODULE_DESCRIPTION("IPv6 packet filter"); 41 42 void *ip6t_alloc_initial_table(const struct xt_table *info) 43 { 44 return xt_alloc_initial_table(ip6t, IP6T); 45 } 46 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table); 47 48 /* Returns whether matches rule or not. */ 49 /* Performance critical - called for every packet */ 50 static inline bool 51 ip6_packet_match(const struct sk_buff *skb, 52 const char *indev, 53 const char *outdev, 54 const struct ip6t_ip6 *ip6info, 55 unsigned int *protoff, 56 int *fragoff, bool *hotdrop) 57 { 58 unsigned long ret; 59 const struct ipv6hdr *ipv6 = ipv6_hdr(skb); 60 61 if (NF_INVF(ip6info, IP6T_INV_SRCIP, 62 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, 63 &ip6info->src)) || 64 NF_INVF(ip6info, IP6T_INV_DSTIP, 65 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, 66 &ip6info->dst))) 67 return false; 68 69 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask); 70 71 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0)) 72 return false; 73 74 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask); 75 76 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0)) 77 return false; 78 79 /* ... might want to do something with class and flowlabel here ... */ 80 81 /* look for the desired protocol header */ 82 if (ip6info->flags & IP6T_F_PROTO) { 83 int protohdr; 84 unsigned short _frag_off; 85 86 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); 87 if (protohdr < 0) { 88 if (_frag_off == 0) 89 *hotdrop = true; 90 return false; 91 } 92 *fragoff = _frag_off; 93 94 if (ip6info->proto == protohdr) { 95 if (ip6info->invflags & IP6T_INV_PROTO) 96 return false; 97 98 return true; 99 } 100 101 /* We need match for the '-p all', too! */ 102 if ((ip6info->proto != 0) && 103 !(ip6info->invflags & IP6T_INV_PROTO)) 104 return false; 105 } 106 return true; 107 } 108 109 /* should be ip6 safe */ 110 static bool 111 ip6_checkentry(const struct ip6t_ip6 *ipv6) 112 { 113 if (ipv6->flags & ~IP6T_F_MASK) 114 return false; 115 if (ipv6->invflags & ~IP6T_INV_MASK) 116 return false; 117 118 return true; 119 } 120 121 static unsigned int 122 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par) 123 { 124 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 125 126 return NF_DROP; 127 } 128 129 static inline struct ip6t_entry * 130 get_entry(const void *base, unsigned int offset) 131 { 132 return (struct ip6t_entry *)(base + offset); 133 } 134 135 /* All zeroes == unconditional rule. */ 136 /* Mildly perf critical (only if packet tracing is on) */ 137 static inline bool unconditional(const struct ip6t_entry *e) 138 { 139 static const struct ip6t_ip6 uncond; 140 141 return e->target_offset == sizeof(struct ip6t_entry) && 142 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0; 143 } 144 145 static inline const struct xt_entry_target * 146 ip6t_get_target_c(const struct ip6t_entry *e) 147 { 148 return ip6t_get_target((struct ip6t_entry *)e); 149 } 150 151 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 152 /* This cries for unification! */ 153 static const char *const hooknames[] = { 154 [NF_INET_PRE_ROUTING] = "PREROUTING", 155 [NF_INET_LOCAL_IN] = "INPUT", 156 [NF_INET_FORWARD] = "FORWARD", 157 [NF_INET_LOCAL_OUT] = "OUTPUT", 158 [NF_INET_POST_ROUTING] = "POSTROUTING", 159 }; 160 161 enum nf_ip_trace_comments { 162 NF_IP6_TRACE_COMMENT_RULE, 163 NF_IP6_TRACE_COMMENT_RETURN, 164 NF_IP6_TRACE_COMMENT_POLICY, 165 }; 166 167 static const char *const comments[] = { 168 [NF_IP6_TRACE_COMMENT_RULE] = "rule", 169 [NF_IP6_TRACE_COMMENT_RETURN] = "return", 170 [NF_IP6_TRACE_COMMENT_POLICY] = "policy", 171 }; 172 173 static const struct nf_loginfo trace_loginfo = { 174 .type = NF_LOG_TYPE_LOG, 175 .u = { 176 .log = { 177 .level = LOGLEVEL_WARNING, 178 .logflags = NF_LOG_DEFAULT_MASK, 179 }, 180 }, 181 }; 182 183 /* Mildly perf critical (only if packet tracing is on) */ 184 static inline int 185 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e, 186 const char *hookname, const char **chainname, 187 const char **comment, unsigned int *rulenum) 188 { 189 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s); 190 191 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 192 /* Head of user chain: ERROR target with chainname */ 193 *chainname = t->target.data; 194 (*rulenum) = 0; 195 } else if (s == e) { 196 (*rulenum)++; 197 198 if (unconditional(s) && 199 strcmp(t->target.u.kernel.target->name, 200 XT_STANDARD_TARGET) == 0 && 201 t->verdict < 0) { 202 /* Tail of chains: STANDARD target (return/policy) */ 203 *comment = *chainname == hookname 204 ? comments[NF_IP6_TRACE_COMMENT_POLICY] 205 : comments[NF_IP6_TRACE_COMMENT_RETURN]; 206 } 207 return 1; 208 } else 209 (*rulenum)++; 210 211 return 0; 212 } 213 214 static void trace_packet(struct net *net, 215 const struct sk_buff *skb, 216 unsigned int hook, 217 const struct net_device *in, 218 const struct net_device *out, 219 const char *tablename, 220 const struct xt_table_info *private, 221 const struct ip6t_entry *e) 222 { 223 const struct ip6t_entry *root; 224 const char *hookname, *chainname, *comment; 225 const struct ip6t_entry *iter; 226 unsigned int rulenum = 0; 227 228 root = get_entry(private->entries, private->hook_entry[hook]); 229 230 hookname = chainname = hooknames[hook]; 231 comment = comments[NF_IP6_TRACE_COMMENT_RULE]; 232 233 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 234 if (get_chainname_rulenum(iter, e, hookname, 235 &chainname, &comment, &rulenum) != 0) 236 break; 237 238 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo, 239 "TRACE: %s:%s:%s:%u ", 240 tablename, chainname, comment, rulenum); 241 } 242 #endif 243 244 static inline struct ip6t_entry * 245 ip6t_next_entry(const struct ip6t_entry *entry) 246 { 247 return (void *)entry + entry->next_offset; 248 } 249 250 /* Returns one of the generic firewall policies, like NF_ACCEPT. */ 251 unsigned int 252 ip6t_do_table(struct sk_buff *skb, 253 const struct nf_hook_state *state, 254 struct xt_table *table) 255 { 256 unsigned int hook = state->hook; 257 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 258 /* Initializing verdict to NF_DROP keeps gcc happy. */ 259 unsigned int verdict = NF_DROP; 260 const char *indev, *outdev; 261 const void *table_base; 262 struct ip6t_entry *e, **jumpstack; 263 unsigned int stackidx, cpu; 264 const struct xt_table_info *private; 265 struct xt_action_param acpar; 266 unsigned int addend; 267 268 /* Initialization */ 269 stackidx = 0; 270 indev = state->in ? state->in->name : nulldevname; 271 outdev = state->out ? state->out->name : nulldevname; 272 /* We handle fragments by dealing with the first fragment as 273 * if it was a normal packet. All other fragments are treated 274 * normally, except that they will NEVER match rules that ask 275 * things we don't know, ie. tcp syn flag or ports). If the 276 * rule is also a fragment-specific rule, non-fragments won't 277 * match it. */ 278 acpar.hotdrop = false; 279 acpar.state = state; 280 281 WARN_ON(!(table->valid_hooks & (1 << hook))); 282 283 local_bh_disable(); 284 addend = xt_write_recseq_begin(); 285 private = table->private; 286 /* 287 * Ensure we load private-> members after we've fetched the base 288 * pointer. 289 */ 290 smp_read_barrier_depends(); 291 cpu = smp_processor_id(); 292 table_base = private->entries; 293 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 294 295 /* Switch to alternate jumpstack if we're being invoked via TEE. 296 * TEE issues XT_CONTINUE verdict on original skb so we must not 297 * clobber the jumpstack. 298 * 299 * For recursion via REJECT or SYNPROXY the stack will be clobbered 300 * but it is no problem since absolute verdict is issued by these. 301 */ 302 if (static_key_false(&xt_tee_enabled)) 303 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); 304 305 e = get_entry(table_base, private->hook_entry[hook]); 306 307 do { 308 const struct xt_entry_target *t; 309 const struct xt_entry_match *ematch; 310 struct xt_counters *counter; 311 312 WARN_ON(!e); 313 acpar.thoff = 0; 314 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 315 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 316 no_match: 317 e = ip6t_next_entry(e); 318 continue; 319 } 320 321 xt_ematch_foreach(ematch, e) { 322 acpar.match = ematch->u.kernel.match; 323 acpar.matchinfo = ematch->data; 324 if (!acpar.match->match(skb, &acpar)) 325 goto no_match; 326 } 327 328 counter = xt_get_this_cpu_counter(&e->counters); 329 ADD_COUNTER(*counter, skb->len, 1); 330 331 t = ip6t_get_target_c(e); 332 WARN_ON(!t->u.kernel.target); 333 334 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 335 /* The packet is traced: log it */ 336 if (unlikely(skb->nf_trace)) 337 trace_packet(state->net, skb, hook, state->in, 338 state->out, table->name, private, e); 339 #endif 340 /* Standard target? */ 341 if (!t->u.kernel.target->target) { 342 int v; 343 344 v = ((struct xt_standard_target *)t)->verdict; 345 if (v < 0) { 346 /* Pop from stack? */ 347 if (v != XT_RETURN) { 348 verdict = (unsigned int)(-v) - 1; 349 break; 350 } 351 if (stackidx == 0) 352 e = get_entry(table_base, 353 private->underflow[hook]); 354 else 355 e = ip6t_next_entry(jumpstack[--stackidx]); 356 continue; 357 } 358 if (table_base + v != ip6t_next_entry(e) && 359 !(e->ipv6.flags & IP6T_F_GOTO)) { 360 jumpstack[stackidx++] = e; 361 } 362 363 e = get_entry(table_base, v); 364 continue; 365 } 366 367 acpar.target = t->u.kernel.target; 368 acpar.targinfo = t->data; 369 370 verdict = t->u.kernel.target->target(skb, &acpar); 371 if (verdict == XT_CONTINUE) 372 e = ip6t_next_entry(e); 373 else 374 /* Verdict */ 375 break; 376 } while (!acpar.hotdrop); 377 378 xt_write_recseq_end(addend); 379 local_bh_enable(); 380 381 if (acpar.hotdrop) 382 return NF_DROP; 383 else return verdict; 384 } 385 386 /* Figures out from what hook each rule can be called: returns 0 if 387 there are loops. Puts hook bitmask in comefrom. */ 388 static int 389 mark_source_chains(const struct xt_table_info *newinfo, 390 unsigned int valid_hooks, void *entry0, 391 unsigned int *offsets) 392 { 393 unsigned int hook; 394 395 /* No recursion; use packet counter to save back ptrs (reset 396 to 0 as we leave), and comefrom to save source hook bitmask */ 397 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 398 unsigned int pos = newinfo->hook_entry[hook]; 399 struct ip6t_entry *e = entry0 + pos; 400 401 if (!(valid_hooks & (1 << hook))) 402 continue; 403 404 /* Set initial back pointer. */ 405 e->counters.pcnt = pos; 406 407 for (;;) { 408 const struct xt_standard_target *t 409 = (void *)ip6t_get_target_c(e); 410 int visited = e->comefrom & (1 << hook); 411 412 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 413 return 0; 414 415 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 416 417 /* Unconditional return/END. */ 418 if ((unconditional(e) && 419 (strcmp(t->target.u.user.name, 420 XT_STANDARD_TARGET) == 0) && 421 t->verdict < 0) || visited) { 422 unsigned int oldpos, size; 423 424 if ((strcmp(t->target.u.user.name, 425 XT_STANDARD_TARGET) == 0) && 426 t->verdict < -NF_MAX_VERDICT - 1) 427 return 0; 428 429 /* Return: backtrack through the last 430 big jump. */ 431 do { 432 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 433 oldpos = pos; 434 pos = e->counters.pcnt; 435 e->counters.pcnt = 0; 436 437 /* We're at the start. */ 438 if (pos == oldpos) 439 goto next; 440 441 e = entry0 + pos; 442 } while (oldpos == pos + e->next_offset); 443 444 /* Move along one */ 445 size = e->next_offset; 446 e = entry0 + pos + size; 447 if (pos + size >= newinfo->size) 448 return 0; 449 e->counters.pcnt = pos; 450 pos += size; 451 } else { 452 int newpos = t->verdict; 453 454 if (strcmp(t->target.u.user.name, 455 XT_STANDARD_TARGET) == 0 && 456 newpos >= 0) { 457 /* This a jump; chase it. */ 458 if (!xt_find_jump_offset(offsets, newpos, 459 newinfo->number)) 460 return 0; 461 e = entry0 + newpos; 462 } else { 463 /* ... this is a fallthru */ 464 newpos = pos + e->next_offset; 465 if (newpos >= newinfo->size) 466 return 0; 467 } 468 e = entry0 + newpos; 469 e->counters.pcnt = pos; 470 pos = newpos; 471 } 472 } 473 next: ; 474 } 475 return 1; 476 } 477 478 static void cleanup_match(struct xt_entry_match *m, struct net *net) 479 { 480 struct xt_mtdtor_param par; 481 482 par.net = net; 483 par.match = m->u.kernel.match; 484 par.matchinfo = m->data; 485 par.family = NFPROTO_IPV6; 486 if (par.match->destroy != NULL) 487 par.match->destroy(&par); 488 module_put(par.match->me); 489 } 490 491 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 492 { 493 const struct ip6t_ip6 *ipv6 = par->entryinfo; 494 495 par->match = m->u.kernel.match; 496 par->matchinfo = m->data; 497 498 return xt_check_match(par, m->u.match_size - sizeof(*m), 499 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 500 } 501 502 static int 503 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 504 { 505 struct xt_match *match; 506 int ret; 507 508 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 509 m->u.user.revision); 510 if (IS_ERR(match)) 511 return PTR_ERR(match); 512 513 m->u.kernel.match = match; 514 515 ret = check_match(m, par); 516 if (ret) 517 goto err; 518 519 return 0; 520 err: 521 module_put(m->u.kernel.match->me); 522 return ret; 523 } 524 525 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 526 { 527 struct xt_entry_target *t = ip6t_get_target(e); 528 struct xt_tgchk_param par = { 529 .net = net, 530 .table = name, 531 .entryinfo = e, 532 .target = t->u.kernel.target, 533 .targinfo = t->data, 534 .hook_mask = e->comefrom, 535 .family = NFPROTO_IPV6, 536 }; 537 538 t = ip6t_get_target(e); 539 return xt_check_target(&par, t->u.target_size - sizeof(*t), 540 e->ipv6.proto, 541 e->ipv6.invflags & IP6T_INV_PROTO); 542 } 543 544 static int 545 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 546 unsigned int size, 547 struct xt_percpu_counter_alloc_state *alloc_state) 548 { 549 struct xt_entry_target *t; 550 struct xt_target *target; 551 int ret; 552 unsigned int j; 553 struct xt_mtchk_param mtpar; 554 struct xt_entry_match *ematch; 555 556 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 557 return -ENOMEM; 558 559 j = 0; 560 mtpar.net = net; 561 mtpar.table = name; 562 mtpar.entryinfo = &e->ipv6; 563 mtpar.hook_mask = e->comefrom; 564 mtpar.family = NFPROTO_IPV6; 565 xt_ematch_foreach(ematch, e) { 566 ret = find_check_match(ematch, &mtpar); 567 if (ret != 0) 568 goto cleanup_matches; 569 ++j; 570 } 571 572 t = ip6t_get_target(e); 573 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 574 t->u.user.revision); 575 if (IS_ERR(target)) { 576 ret = PTR_ERR(target); 577 goto cleanup_matches; 578 } 579 t->u.kernel.target = target; 580 581 ret = check_target(e, net, name); 582 if (ret) 583 goto err; 584 return 0; 585 err: 586 module_put(t->u.kernel.target->me); 587 cleanup_matches: 588 xt_ematch_foreach(ematch, e) { 589 if (j-- == 0) 590 break; 591 cleanup_match(ematch, net); 592 } 593 594 xt_percpu_counter_free(&e->counters); 595 596 return ret; 597 } 598 599 static bool check_underflow(const struct ip6t_entry *e) 600 { 601 const struct xt_entry_target *t; 602 unsigned int verdict; 603 604 if (!unconditional(e)) 605 return false; 606 t = ip6t_get_target_c(e); 607 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 608 return false; 609 verdict = ((struct xt_standard_target *)t)->verdict; 610 verdict = -verdict - 1; 611 return verdict == NF_DROP || verdict == NF_ACCEPT; 612 } 613 614 static int 615 check_entry_size_and_hooks(struct ip6t_entry *e, 616 struct xt_table_info *newinfo, 617 const unsigned char *base, 618 const unsigned char *limit, 619 const unsigned int *hook_entries, 620 const unsigned int *underflows, 621 unsigned int valid_hooks) 622 { 623 unsigned int h; 624 int err; 625 626 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 627 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 628 (unsigned char *)e + e->next_offset > limit) 629 return -EINVAL; 630 631 if (e->next_offset 632 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 633 return -EINVAL; 634 635 if (!ip6_checkentry(&e->ipv6)) 636 return -EINVAL; 637 638 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 639 e->next_offset); 640 if (err) 641 return err; 642 643 /* Check hooks & underflows */ 644 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 645 if (!(valid_hooks & (1 << h))) 646 continue; 647 if ((unsigned char *)e - base == hook_entries[h]) 648 newinfo->hook_entry[h] = hook_entries[h]; 649 if ((unsigned char *)e - base == underflows[h]) { 650 if (!check_underflow(e)) 651 return -EINVAL; 652 653 newinfo->underflow[h] = underflows[h]; 654 } 655 } 656 657 /* Clear counters and comefrom */ 658 e->counters = ((struct xt_counters) { 0, 0 }); 659 e->comefrom = 0; 660 return 0; 661 } 662 663 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 664 { 665 struct xt_tgdtor_param par; 666 struct xt_entry_target *t; 667 struct xt_entry_match *ematch; 668 669 /* Cleanup all matches */ 670 xt_ematch_foreach(ematch, e) 671 cleanup_match(ematch, net); 672 t = ip6t_get_target(e); 673 674 par.net = net; 675 par.target = t->u.kernel.target; 676 par.targinfo = t->data; 677 par.family = NFPROTO_IPV6; 678 if (par.target->destroy != NULL) 679 par.target->destroy(&par); 680 module_put(par.target->me); 681 xt_percpu_counter_free(&e->counters); 682 } 683 684 /* Checks and translates the user-supplied table segment (held in 685 newinfo) */ 686 static int 687 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 688 const struct ip6t_replace *repl) 689 { 690 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 691 struct ip6t_entry *iter; 692 unsigned int *offsets; 693 unsigned int i; 694 int ret = 0; 695 696 newinfo->size = repl->size; 697 newinfo->number = repl->num_entries; 698 699 /* Init all hooks to impossible value. */ 700 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 701 newinfo->hook_entry[i] = 0xFFFFFFFF; 702 newinfo->underflow[i] = 0xFFFFFFFF; 703 } 704 705 offsets = xt_alloc_entry_offsets(newinfo->number); 706 if (!offsets) 707 return -ENOMEM; 708 i = 0; 709 /* Walk through entries, checking offsets. */ 710 xt_entry_foreach(iter, entry0, newinfo->size) { 711 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 712 entry0 + repl->size, 713 repl->hook_entry, 714 repl->underflow, 715 repl->valid_hooks); 716 if (ret != 0) 717 goto out_free; 718 if (i < repl->num_entries) 719 offsets[i] = (void *)iter - entry0; 720 ++i; 721 if (strcmp(ip6t_get_target(iter)->u.user.name, 722 XT_ERROR_TARGET) == 0) 723 ++newinfo->stacksize; 724 } 725 726 ret = -EINVAL; 727 if (i != repl->num_entries) 728 goto out_free; 729 730 /* Check hooks all assigned */ 731 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 732 /* Only hooks which are valid */ 733 if (!(repl->valid_hooks & (1 << i))) 734 continue; 735 if (newinfo->hook_entry[i] == 0xFFFFFFFF) 736 goto out_free; 737 if (newinfo->underflow[i] == 0xFFFFFFFF) 738 goto out_free; 739 } 740 741 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 742 ret = -ELOOP; 743 goto out_free; 744 } 745 kvfree(offsets); 746 747 /* Finally, each sanity check must pass */ 748 i = 0; 749 xt_entry_foreach(iter, entry0, newinfo->size) { 750 ret = find_check_entry(iter, net, repl->name, repl->size, 751 &alloc_state); 752 if (ret != 0) 753 break; 754 ++i; 755 } 756 757 if (ret != 0) { 758 xt_entry_foreach(iter, entry0, newinfo->size) { 759 if (i-- == 0) 760 break; 761 cleanup_entry(iter, net); 762 } 763 return ret; 764 } 765 766 return ret; 767 out_free: 768 kvfree(offsets); 769 return ret; 770 } 771 772 static void 773 get_counters(const struct xt_table_info *t, 774 struct xt_counters counters[]) 775 { 776 struct ip6t_entry *iter; 777 unsigned int cpu; 778 unsigned int i; 779 780 for_each_possible_cpu(cpu) { 781 seqcount_t *s = &per_cpu(xt_recseq, cpu); 782 783 i = 0; 784 xt_entry_foreach(iter, t->entries, t->size) { 785 struct xt_counters *tmp; 786 u64 bcnt, pcnt; 787 unsigned int start; 788 789 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 790 do { 791 start = read_seqcount_begin(s); 792 bcnt = tmp->bcnt; 793 pcnt = tmp->pcnt; 794 } while (read_seqcount_retry(s, start)); 795 796 ADD_COUNTER(counters[i], bcnt, pcnt); 797 ++i; 798 cond_resched(); 799 } 800 } 801 } 802 803 static struct xt_counters *alloc_counters(const struct xt_table *table) 804 { 805 unsigned int countersize; 806 struct xt_counters *counters; 807 const struct xt_table_info *private = table->private; 808 809 /* We need atomic snapshot of counters: rest doesn't change 810 (other than comefrom, which userspace doesn't care 811 about). */ 812 countersize = sizeof(struct xt_counters) * private->number; 813 counters = vzalloc(countersize); 814 815 if (counters == NULL) 816 return ERR_PTR(-ENOMEM); 817 818 get_counters(private, counters); 819 820 return counters; 821 } 822 823 static int 824 copy_entries_to_user(unsigned int total_size, 825 const struct xt_table *table, 826 void __user *userptr) 827 { 828 unsigned int off, num; 829 const struct ip6t_entry *e; 830 struct xt_counters *counters; 831 const struct xt_table_info *private = table->private; 832 int ret = 0; 833 const void *loc_cpu_entry; 834 835 counters = alloc_counters(table); 836 if (IS_ERR(counters)) 837 return PTR_ERR(counters); 838 839 loc_cpu_entry = private->entries; 840 841 /* FIXME: use iterator macros --RR */ 842 /* ... then go back and fix counters and names */ 843 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 844 unsigned int i; 845 const struct xt_entry_match *m; 846 const struct xt_entry_target *t; 847 848 e = loc_cpu_entry + off; 849 if (copy_to_user(userptr + off, e, sizeof(*e))) { 850 ret = -EFAULT; 851 goto free_counters; 852 } 853 if (copy_to_user(userptr + off 854 + offsetof(struct ip6t_entry, counters), 855 &counters[num], 856 sizeof(counters[num])) != 0) { 857 ret = -EFAULT; 858 goto free_counters; 859 } 860 861 for (i = sizeof(struct ip6t_entry); 862 i < e->target_offset; 863 i += m->u.match_size) { 864 m = (void *)e + i; 865 866 if (xt_match_to_user(m, userptr + off + i)) { 867 ret = -EFAULT; 868 goto free_counters; 869 } 870 } 871 872 t = ip6t_get_target_c(e); 873 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 874 ret = -EFAULT; 875 goto free_counters; 876 } 877 } 878 879 free_counters: 880 vfree(counters); 881 return ret; 882 } 883 884 #ifdef CONFIG_COMPAT 885 static void compat_standard_from_user(void *dst, const void *src) 886 { 887 int v = *(compat_int_t *)src; 888 889 if (v > 0) 890 v += xt_compat_calc_jump(AF_INET6, v); 891 memcpy(dst, &v, sizeof(v)); 892 } 893 894 static int compat_standard_to_user(void __user *dst, const void *src) 895 { 896 compat_int_t cv = *(int *)src; 897 898 if (cv > 0) 899 cv -= xt_compat_calc_jump(AF_INET6, cv); 900 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 901 } 902 903 static int compat_calc_entry(const struct ip6t_entry *e, 904 const struct xt_table_info *info, 905 const void *base, struct xt_table_info *newinfo) 906 { 907 const struct xt_entry_match *ematch; 908 const struct xt_entry_target *t; 909 unsigned int entry_offset; 910 int off, i, ret; 911 912 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 913 entry_offset = (void *)e - base; 914 xt_ematch_foreach(ematch, e) 915 off += xt_compat_match_offset(ematch->u.kernel.match); 916 t = ip6t_get_target_c(e); 917 off += xt_compat_target_offset(t->u.kernel.target); 918 newinfo->size -= off; 919 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 920 if (ret) 921 return ret; 922 923 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 924 if (info->hook_entry[i] && 925 (e < (struct ip6t_entry *)(base + info->hook_entry[i]))) 926 newinfo->hook_entry[i] -= off; 927 if (info->underflow[i] && 928 (e < (struct ip6t_entry *)(base + info->underflow[i]))) 929 newinfo->underflow[i] -= off; 930 } 931 return 0; 932 } 933 934 static int compat_table_info(const struct xt_table_info *info, 935 struct xt_table_info *newinfo) 936 { 937 struct ip6t_entry *iter; 938 const void *loc_cpu_entry; 939 int ret; 940 941 if (!newinfo || !info) 942 return -EINVAL; 943 944 /* we dont care about newinfo->entries */ 945 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 946 newinfo->initial_entries = 0; 947 loc_cpu_entry = info->entries; 948 xt_compat_init_offsets(AF_INET6, info->number); 949 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 950 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 951 if (ret != 0) 952 return ret; 953 } 954 return 0; 955 } 956 #endif 957 958 static int get_info(struct net *net, void __user *user, 959 const int *len, int compat) 960 { 961 char name[XT_TABLE_MAXNAMELEN]; 962 struct xt_table *t; 963 int ret; 964 965 if (*len != sizeof(struct ip6t_getinfo)) 966 return -EINVAL; 967 968 if (copy_from_user(name, user, sizeof(name)) != 0) 969 return -EFAULT; 970 971 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 972 #ifdef CONFIG_COMPAT 973 if (compat) 974 xt_compat_lock(AF_INET6); 975 #endif 976 t = try_then_request_module(xt_find_table_lock(net, AF_INET6, name), 977 "ip6table_%s", name); 978 if (t) { 979 struct ip6t_getinfo info; 980 const struct xt_table_info *private = t->private; 981 #ifdef CONFIG_COMPAT 982 struct xt_table_info tmp; 983 984 if (compat) { 985 ret = compat_table_info(private, &tmp); 986 xt_compat_flush_offsets(AF_INET6); 987 private = &tmp; 988 } 989 #endif 990 memset(&info, 0, sizeof(info)); 991 info.valid_hooks = t->valid_hooks; 992 memcpy(info.hook_entry, private->hook_entry, 993 sizeof(info.hook_entry)); 994 memcpy(info.underflow, private->underflow, 995 sizeof(info.underflow)); 996 info.num_entries = private->number; 997 info.size = private->size; 998 strcpy(info.name, name); 999 1000 if (copy_to_user(user, &info, *len) != 0) 1001 ret = -EFAULT; 1002 else 1003 ret = 0; 1004 1005 xt_table_unlock(t); 1006 module_put(t->me); 1007 } else 1008 ret = -ENOENT; 1009 #ifdef CONFIG_COMPAT 1010 if (compat) 1011 xt_compat_unlock(AF_INET6); 1012 #endif 1013 return ret; 1014 } 1015 1016 static int 1017 get_entries(struct net *net, struct ip6t_get_entries __user *uptr, 1018 const int *len) 1019 { 1020 int ret; 1021 struct ip6t_get_entries get; 1022 struct xt_table *t; 1023 1024 if (*len < sizeof(get)) 1025 return -EINVAL; 1026 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1027 return -EFAULT; 1028 if (*len != sizeof(struct ip6t_get_entries) + get.size) 1029 return -EINVAL; 1030 1031 get.name[sizeof(get.name) - 1] = '\0'; 1032 1033 t = xt_find_table_lock(net, AF_INET6, get.name); 1034 if (t) { 1035 struct xt_table_info *private = t->private; 1036 if (get.size == private->size) 1037 ret = copy_entries_to_user(private->size, 1038 t, uptr->entrytable); 1039 else 1040 ret = -EAGAIN; 1041 1042 module_put(t->me); 1043 xt_table_unlock(t); 1044 } else 1045 ret = -ENOENT; 1046 1047 return ret; 1048 } 1049 1050 static int 1051 __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1052 struct xt_table_info *newinfo, unsigned int num_counters, 1053 void __user *counters_ptr) 1054 { 1055 int ret; 1056 struct xt_table *t; 1057 struct xt_table_info *oldinfo; 1058 struct xt_counters *counters; 1059 struct ip6t_entry *iter; 1060 1061 ret = 0; 1062 counters = vzalloc(num_counters * sizeof(struct xt_counters)); 1063 if (!counters) { 1064 ret = -ENOMEM; 1065 goto out; 1066 } 1067 1068 t = try_then_request_module(xt_find_table_lock(net, AF_INET6, name), 1069 "ip6table_%s", name); 1070 if (!t) { 1071 ret = -ENOENT; 1072 goto free_newinfo_counters_untrans; 1073 } 1074 1075 /* You lied! */ 1076 if (valid_hooks != t->valid_hooks) { 1077 ret = -EINVAL; 1078 goto put_module; 1079 } 1080 1081 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1082 if (!oldinfo) 1083 goto put_module; 1084 1085 /* Update module usage count based on number of rules */ 1086 if ((oldinfo->number > oldinfo->initial_entries) || 1087 (newinfo->number <= oldinfo->initial_entries)) 1088 module_put(t->me); 1089 if ((oldinfo->number > oldinfo->initial_entries) && 1090 (newinfo->number <= oldinfo->initial_entries)) 1091 module_put(t->me); 1092 1093 /* Get the old counters, and synchronize with replace */ 1094 get_counters(oldinfo, counters); 1095 1096 /* Decrease module usage counts and free resource */ 1097 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1098 cleanup_entry(iter, net); 1099 1100 xt_free_table_info(oldinfo); 1101 if (copy_to_user(counters_ptr, counters, 1102 sizeof(struct xt_counters) * num_counters) != 0) { 1103 /* Silent error, can't fail, new table is already in place */ 1104 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1105 } 1106 vfree(counters); 1107 xt_table_unlock(t); 1108 return ret; 1109 1110 put_module: 1111 module_put(t->me); 1112 xt_table_unlock(t); 1113 free_newinfo_counters_untrans: 1114 vfree(counters); 1115 out: 1116 return ret; 1117 } 1118 1119 static int 1120 do_replace(struct net *net, const void __user *user, unsigned int len) 1121 { 1122 int ret; 1123 struct ip6t_replace tmp; 1124 struct xt_table_info *newinfo; 1125 void *loc_cpu_entry; 1126 struct ip6t_entry *iter; 1127 1128 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1129 return -EFAULT; 1130 1131 /* overflow check */ 1132 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1133 return -ENOMEM; 1134 if (tmp.num_counters == 0) 1135 return -EINVAL; 1136 1137 tmp.name[sizeof(tmp.name)-1] = 0; 1138 1139 newinfo = xt_alloc_table_info(tmp.size); 1140 if (!newinfo) 1141 return -ENOMEM; 1142 1143 loc_cpu_entry = newinfo->entries; 1144 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1145 tmp.size) != 0) { 1146 ret = -EFAULT; 1147 goto free_newinfo; 1148 } 1149 1150 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1151 if (ret != 0) 1152 goto free_newinfo; 1153 1154 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1155 tmp.num_counters, tmp.counters); 1156 if (ret) 1157 goto free_newinfo_untrans; 1158 return 0; 1159 1160 free_newinfo_untrans: 1161 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1162 cleanup_entry(iter, net); 1163 free_newinfo: 1164 xt_free_table_info(newinfo); 1165 return ret; 1166 } 1167 1168 static int 1169 do_add_counters(struct net *net, const void __user *user, unsigned int len, 1170 int compat) 1171 { 1172 unsigned int i; 1173 struct xt_counters_info tmp; 1174 struct xt_counters *paddc; 1175 struct xt_table *t; 1176 const struct xt_table_info *private; 1177 int ret = 0; 1178 struct ip6t_entry *iter; 1179 unsigned int addend; 1180 1181 paddc = xt_copy_counters_from_user(user, len, &tmp, compat); 1182 if (IS_ERR(paddc)) 1183 return PTR_ERR(paddc); 1184 t = xt_find_table_lock(net, AF_INET6, tmp.name); 1185 if (!t) { 1186 ret = -ENOENT; 1187 goto free; 1188 } 1189 1190 local_bh_disable(); 1191 private = t->private; 1192 if (private->number != tmp.num_counters) { 1193 ret = -EINVAL; 1194 goto unlock_up_free; 1195 } 1196 1197 i = 0; 1198 addend = xt_write_recseq_begin(); 1199 xt_entry_foreach(iter, private->entries, private->size) { 1200 struct xt_counters *tmp; 1201 1202 tmp = xt_get_this_cpu_counter(&iter->counters); 1203 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); 1204 ++i; 1205 } 1206 xt_write_recseq_end(addend); 1207 unlock_up_free: 1208 local_bh_enable(); 1209 xt_table_unlock(t); 1210 module_put(t->me); 1211 free: 1212 vfree(paddc); 1213 1214 return ret; 1215 } 1216 1217 #ifdef CONFIG_COMPAT 1218 struct compat_ip6t_replace { 1219 char name[XT_TABLE_MAXNAMELEN]; 1220 u32 valid_hooks; 1221 u32 num_entries; 1222 u32 size; 1223 u32 hook_entry[NF_INET_NUMHOOKS]; 1224 u32 underflow[NF_INET_NUMHOOKS]; 1225 u32 num_counters; 1226 compat_uptr_t counters; /* struct xt_counters * */ 1227 struct compat_ip6t_entry entries[0]; 1228 }; 1229 1230 static int 1231 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr, 1232 unsigned int *size, struct xt_counters *counters, 1233 unsigned int i) 1234 { 1235 struct xt_entry_target *t; 1236 struct compat_ip6t_entry __user *ce; 1237 u_int16_t target_offset, next_offset; 1238 compat_uint_t origsize; 1239 const struct xt_entry_match *ematch; 1240 int ret = 0; 1241 1242 origsize = *size; 1243 ce = *dstptr; 1244 if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 || 1245 copy_to_user(&ce->counters, &counters[i], 1246 sizeof(counters[i])) != 0) 1247 return -EFAULT; 1248 1249 *dstptr += sizeof(struct compat_ip6t_entry); 1250 *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1251 1252 xt_ematch_foreach(ematch, e) { 1253 ret = xt_compat_match_to_user(ematch, dstptr, size); 1254 if (ret != 0) 1255 return ret; 1256 } 1257 target_offset = e->target_offset - (origsize - *size); 1258 t = ip6t_get_target(e); 1259 ret = xt_compat_target_to_user(t, dstptr, size); 1260 if (ret) 1261 return ret; 1262 next_offset = e->next_offset - (origsize - *size); 1263 if (put_user(target_offset, &ce->target_offset) != 0 || 1264 put_user(next_offset, &ce->next_offset) != 0) 1265 return -EFAULT; 1266 return 0; 1267 } 1268 1269 static int 1270 compat_find_calc_match(struct xt_entry_match *m, 1271 const struct ip6t_ip6 *ipv6, 1272 int *size) 1273 { 1274 struct xt_match *match; 1275 1276 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 1277 m->u.user.revision); 1278 if (IS_ERR(match)) 1279 return PTR_ERR(match); 1280 1281 m->u.kernel.match = match; 1282 *size += xt_compat_match_offset(match); 1283 return 0; 1284 } 1285 1286 static void compat_release_entry(struct compat_ip6t_entry *e) 1287 { 1288 struct xt_entry_target *t; 1289 struct xt_entry_match *ematch; 1290 1291 /* Cleanup all matches */ 1292 xt_ematch_foreach(ematch, e) 1293 module_put(ematch->u.kernel.match->me); 1294 t = compat_ip6t_get_target(e); 1295 module_put(t->u.kernel.target->me); 1296 } 1297 1298 static int 1299 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, 1300 struct xt_table_info *newinfo, 1301 unsigned int *size, 1302 const unsigned char *base, 1303 const unsigned char *limit) 1304 { 1305 struct xt_entry_match *ematch; 1306 struct xt_entry_target *t; 1307 struct xt_target *target; 1308 unsigned int entry_offset; 1309 unsigned int j; 1310 int ret, off; 1311 1312 if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 || 1313 (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit || 1314 (unsigned char *)e + e->next_offset > limit) 1315 return -EINVAL; 1316 1317 if (e->next_offset < sizeof(struct compat_ip6t_entry) + 1318 sizeof(struct compat_xt_entry_target)) 1319 return -EINVAL; 1320 1321 if (!ip6_checkentry(&e->ipv6)) 1322 return -EINVAL; 1323 1324 ret = xt_compat_check_entry_offsets(e, e->elems, 1325 e->target_offset, e->next_offset); 1326 if (ret) 1327 return ret; 1328 1329 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1330 entry_offset = (void *)e - (void *)base; 1331 j = 0; 1332 xt_ematch_foreach(ematch, e) { 1333 ret = compat_find_calc_match(ematch, &e->ipv6, &off); 1334 if (ret != 0) 1335 goto release_matches; 1336 ++j; 1337 } 1338 1339 t = compat_ip6t_get_target(e); 1340 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 1341 t->u.user.revision); 1342 if (IS_ERR(target)) { 1343 ret = PTR_ERR(target); 1344 goto release_matches; 1345 } 1346 t->u.kernel.target = target; 1347 1348 off += xt_compat_target_offset(target); 1349 *size += off; 1350 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 1351 if (ret) 1352 goto out; 1353 1354 return 0; 1355 1356 out: 1357 module_put(t->u.kernel.target->me); 1358 release_matches: 1359 xt_ematch_foreach(ematch, e) { 1360 if (j-- == 0) 1361 break; 1362 module_put(ematch->u.kernel.match->me); 1363 } 1364 return ret; 1365 } 1366 1367 static void 1368 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, 1369 unsigned int *size, 1370 struct xt_table_info *newinfo, unsigned char *base) 1371 { 1372 struct xt_entry_target *t; 1373 struct ip6t_entry *de; 1374 unsigned int origsize; 1375 int h; 1376 struct xt_entry_match *ematch; 1377 1378 origsize = *size; 1379 de = *dstptr; 1380 memcpy(de, e, sizeof(struct ip6t_entry)); 1381 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1382 1383 *dstptr += sizeof(struct ip6t_entry); 1384 *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1385 1386 xt_ematch_foreach(ematch, e) 1387 xt_compat_match_from_user(ematch, dstptr, size); 1388 1389 de->target_offset = e->target_offset - (origsize - *size); 1390 t = compat_ip6t_get_target(e); 1391 xt_compat_target_from_user(t, dstptr, size); 1392 1393 de->next_offset = e->next_offset - (origsize - *size); 1394 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 1395 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1396 newinfo->hook_entry[h] -= origsize - *size; 1397 if ((unsigned char *)de - base < newinfo->underflow[h]) 1398 newinfo->underflow[h] -= origsize - *size; 1399 } 1400 } 1401 1402 static int 1403 translate_compat_table(struct net *net, 1404 struct xt_table_info **pinfo, 1405 void **pentry0, 1406 const struct compat_ip6t_replace *compatr) 1407 { 1408 unsigned int i, j; 1409 struct xt_table_info *newinfo, *info; 1410 void *pos, *entry0, *entry1; 1411 struct compat_ip6t_entry *iter0; 1412 struct ip6t_replace repl; 1413 unsigned int size; 1414 int ret = 0; 1415 1416 info = *pinfo; 1417 entry0 = *pentry0; 1418 size = compatr->size; 1419 info->number = compatr->num_entries; 1420 1421 j = 0; 1422 xt_compat_lock(AF_INET6); 1423 xt_compat_init_offsets(AF_INET6, compatr->num_entries); 1424 /* Walk through entries, checking offsets. */ 1425 xt_entry_foreach(iter0, entry0, compatr->size) { 1426 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1427 entry0, 1428 entry0 + compatr->size); 1429 if (ret != 0) 1430 goto out_unlock; 1431 ++j; 1432 } 1433 1434 ret = -EINVAL; 1435 if (j != compatr->num_entries) 1436 goto out_unlock; 1437 1438 ret = -ENOMEM; 1439 newinfo = xt_alloc_table_info(size); 1440 if (!newinfo) 1441 goto out_unlock; 1442 1443 newinfo->number = compatr->num_entries; 1444 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1445 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1446 newinfo->underflow[i] = compatr->underflow[i]; 1447 } 1448 entry1 = newinfo->entries; 1449 pos = entry1; 1450 size = compatr->size; 1451 xt_entry_foreach(iter0, entry0, compatr->size) 1452 compat_copy_entry_from_user(iter0, &pos, &size, 1453 newinfo, entry1); 1454 1455 /* all module references in entry0 are now gone. */ 1456 xt_compat_flush_offsets(AF_INET6); 1457 xt_compat_unlock(AF_INET6); 1458 1459 memcpy(&repl, compatr, sizeof(*compatr)); 1460 1461 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1462 repl.hook_entry[i] = newinfo->hook_entry[i]; 1463 repl.underflow[i] = newinfo->underflow[i]; 1464 } 1465 1466 repl.num_counters = 0; 1467 repl.counters = NULL; 1468 repl.size = newinfo->size; 1469 ret = translate_table(net, newinfo, entry1, &repl); 1470 if (ret) 1471 goto free_newinfo; 1472 1473 *pinfo = newinfo; 1474 *pentry0 = entry1; 1475 xt_free_table_info(info); 1476 return 0; 1477 1478 free_newinfo: 1479 xt_free_table_info(newinfo); 1480 return ret; 1481 out_unlock: 1482 xt_compat_flush_offsets(AF_INET6); 1483 xt_compat_unlock(AF_INET6); 1484 xt_entry_foreach(iter0, entry0, compatr->size) { 1485 if (j-- == 0) 1486 break; 1487 compat_release_entry(iter0); 1488 } 1489 return ret; 1490 } 1491 1492 static int 1493 compat_do_replace(struct net *net, void __user *user, unsigned int len) 1494 { 1495 int ret; 1496 struct compat_ip6t_replace tmp; 1497 struct xt_table_info *newinfo; 1498 void *loc_cpu_entry; 1499 struct ip6t_entry *iter; 1500 1501 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1502 return -EFAULT; 1503 1504 /* overflow check */ 1505 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1506 return -ENOMEM; 1507 if (tmp.num_counters == 0) 1508 return -EINVAL; 1509 1510 tmp.name[sizeof(tmp.name)-1] = 0; 1511 1512 newinfo = xt_alloc_table_info(tmp.size); 1513 if (!newinfo) 1514 return -ENOMEM; 1515 1516 loc_cpu_entry = newinfo->entries; 1517 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1518 tmp.size) != 0) { 1519 ret = -EFAULT; 1520 goto free_newinfo; 1521 } 1522 1523 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1524 if (ret != 0) 1525 goto free_newinfo; 1526 1527 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1528 tmp.num_counters, compat_ptr(tmp.counters)); 1529 if (ret) 1530 goto free_newinfo_untrans; 1531 return 0; 1532 1533 free_newinfo_untrans: 1534 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1535 cleanup_entry(iter, net); 1536 free_newinfo: 1537 xt_free_table_info(newinfo); 1538 return ret; 1539 } 1540 1541 static int 1542 compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, 1543 unsigned int len) 1544 { 1545 int ret; 1546 1547 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1548 return -EPERM; 1549 1550 switch (cmd) { 1551 case IP6T_SO_SET_REPLACE: 1552 ret = compat_do_replace(sock_net(sk), user, len); 1553 break; 1554 1555 case IP6T_SO_SET_ADD_COUNTERS: 1556 ret = do_add_counters(sock_net(sk), user, len, 1); 1557 break; 1558 1559 default: 1560 ret = -EINVAL; 1561 } 1562 1563 return ret; 1564 } 1565 1566 struct compat_ip6t_get_entries { 1567 char name[XT_TABLE_MAXNAMELEN]; 1568 compat_uint_t size; 1569 struct compat_ip6t_entry entrytable[0]; 1570 }; 1571 1572 static int 1573 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1574 void __user *userptr) 1575 { 1576 struct xt_counters *counters; 1577 const struct xt_table_info *private = table->private; 1578 void __user *pos; 1579 unsigned int size; 1580 int ret = 0; 1581 unsigned int i = 0; 1582 struct ip6t_entry *iter; 1583 1584 counters = alloc_counters(table); 1585 if (IS_ERR(counters)) 1586 return PTR_ERR(counters); 1587 1588 pos = userptr; 1589 size = total_size; 1590 xt_entry_foreach(iter, private->entries, total_size) { 1591 ret = compat_copy_entry_to_user(iter, &pos, 1592 &size, counters, i++); 1593 if (ret != 0) 1594 break; 1595 } 1596 1597 vfree(counters); 1598 return ret; 1599 } 1600 1601 static int 1602 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1603 int *len) 1604 { 1605 int ret; 1606 struct compat_ip6t_get_entries get; 1607 struct xt_table *t; 1608 1609 if (*len < sizeof(get)) 1610 return -EINVAL; 1611 1612 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1613 return -EFAULT; 1614 1615 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1616 return -EINVAL; 1617 1618 get.name[sizeof(get.name) - 1] = '\0'; 1619 1620 xt_compat_lock(AF_INET6); 1621 t = xt_find_table_lock(net, AF_INET6, get.name); 1622 if (t) { 1623 const struct xt_table_info *private = t->private; 1624 struct xt_table_info info; 1625 ret = compat_table_info(private, &info); 1626 if (!ret && get.size == info.size) 1627 ret = compat_copy_entries_to_user(private->size, 1628 t, uptr->entrytable); 1629 else if (!ret) 1630 ret = -EAGAIN; 1631 1632 xt_compat_flush_offsets(AF_INET6); 1633 module_put(t->me); 1634 xt_table_unlock(t); 1635 } else 1636 ret = -ENOENT; 1637 1638 xt_compat_unlock(AF_INET6); 1639 return ret; 1640 } 1641 1642 static int do_ip6t_get_ctl(struct sock *, int, void __user *, int *); 1643 1644 static int 1645 compat_do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1646 { 1647 int ret; 1648 1649 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1650 return -EPERM; 1651 1652 switch (cmd) { 1653 case IP6T_SO_GET_INFO: 1654 ret = get_info(sock_net(sk), user, len, 1); 1655 break; 1656 case IP6T_SO_GET_ENTRIES: 1657 ret = compat_get_entries(sock_net(sk), user, len); 1658 break; 1659 default: 1660 ret = do_ip6t_get_ctl(sk, cmd, user, len); 1661 } 1662 return ret; 1663 } 1664 #endif 1665 1666 static int 1667 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) 1668 { 1669 int ret; 1670 1671 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1672 return -EPERM; 1673 1674 switch (cmd) { 1675 case IP6T_SO_SET_REPLACE: 1676 ret = do_replace(sock_net(sk), user, len); 1677 break; 1678 1679 case IP6T_SO_SET_ADD_COUNTERS: 1680 ret = do_add_counters(sock_net(sk), user, len, 0); 1681 break; 1682 1683 default: 1684 ret = -EINVAL; 1685 } 1686 1687 return ret; 1688 } 1689 1690 static int 1691 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1692 { 1693 int ret; 1694 1695 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1696 return -EPERM; 1697 1698 switch (cmd) { 1699 case IP6T_SO_GET_INFO: 1700 ret = get_info(sock_net(sk), user, len, 0); 1701 break; 1702 1703 case IP6T_SO_GET_ENTRIES: 1704 ret = get_entries(sock_net(sk), user, len); 1705 break; 1706 1707 case IP6T_SO_GET_REVISION_MATCH: 1708 case IP6T_SO_GET_REVISION_TARGET: { 1709 struct xt_get_revision rev; 1710 int target; 1711 1712 if (*len != sizeof(rev)) { 1713 ret = -EINVAL; 1714 break; 1715 } 1716 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1717 ret = -EFAULT; 1718 break; 1719 } 1720 rev.name[sizeof(rev.name)-1] = 0; 1721 1722 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1723 target = 1; 1724 else 1725 target = 0; 1726 1727 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1728 rev.revision, 1729 target, &ret), 1730 "ip6t_%s", rev.name); 1731 break; 1732 } 1733 1734 default: 1735 ret = -EINVAL; 1736 } 1737 1738 return ret; 1739 } 1740 1741 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1742 { 1743 struct xt_table_info *private; 1744 void *loc_cpu_entry; 1745 struct module *table_owner = table->me; 1746 struct ip6t_entry *iter; 1747 1748 private = xt_unregister_table(table); 1749 1750 /* Decrease module usage counts and free resources */ 1751 loc_cpu_entry = private->entries; 1752 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1753 cleanup_entry(iter, net); 1754 if (private->number > private->initial_entries) 1755 module_put(table_owner); 1756 xt_free_table_info(private); 1757 } 1758 1759 int ip6t_register_table(struct net *net, const struct xt_table *table, 1760 const struct ip6t_replace *repl, 1761 const struct nf_hook_ops *ops, 1762 struct xt_table **res) 1763 { 1764 int ret; 1765 struct xt_table_info *newinfo; 1766 struct xt_table_info bootstrap = {0}; 1767 void *loc_cpu_entry; 1768 struct xt_table *new_table; 1769 1770 newinfo = xt_alloc_table_info(repl->size); 1771 if (!newinfo) 1772 return -ENOMEM; 1773 1774 loc_cpu_entry = newinfo->entries; 1775 memcpy(loc_cpu_entry, repl->entries, repl->size); 1776 1777 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1778 if (ret != 0) 1779 goto out_free; 1780 1781 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1782 if (IS_ERR(new_table)) { 1783 ret = PTR_ERR(new_table); 1784 goto out_free; 1785 } 1786 1787 /* set res now, will see skbs right after nf_register_net_hooks */ 1788 WRITE_ONCE(*res, new_table); 1789 1790 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); 1791 if (ret != 0) { 1792 __ip6t_unregister_table(net, new_table); 1793 *res = NULL; 1794 } 1795 1796 return ret; 1797 1798 out_free: 1799 xt_free_table_info(newinfo); 1800 return ret; 1801 } 1802 1803 void ip6t_unregister_table(struct net *net, struct xt_table *table, 1804 const struct nf_hook_ops *ops) 1805 { 1806 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); 1807 __ip6t_unregister_table(net, table); 1808 } 1809 1810 /* Returns 1 if the type and code is matched by the range, 0 otherwise */ 1811 static inline bool 1812 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, 1813 u_int8_t type, u_int8_t code, 1814 bool invert) 1815 { 1816 return (type == test_type && code >= min_code && code <= max_code) 1817 ^ invert; 1818 } 1819 1820 static bool 1821 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par) 1822 { 1823 const struct icmp6hdr *ic; 1824 struct icmp6hdr _icmph; 1825 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1826 1827 /* Must not be a fragment. */ 1828 if (par->fragoff != 0) 1829 return false; 1830 1831 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); 1832 if (ic == NULL) { 1833 /* We've been asked to examine this packet, and we 1834 * can't. Hence, no choice but to drop. 1835 */ 1836 par->hotdrop = true; 1837 return false; 1838 } 1839 1840 return icmp6_type_code_match(icmpinfo->type, 1841 icmpinfo->code[0], 1842 icmpinfo->code[1], 1843 ic->icmp6_type, ic->icmp6_code, 1844 !!(icmpinfo->invflags&IP6T_ICMP_INV)); 1845 } 1846 1847 /* Called when user tries to insert an entry of this type. */ 1848 static int icmp6_checkentry(const struct xt_mtchk_param *par) 1849 { 1850 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1851 1852 /* Must specify no unknown invflags */ 1853 return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0; 1854 } 1855 1856 /* The built-in targets: standard (NULL) and error. */ 1857 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1858 { 1859 .name = XT_STANDARD_TARGET, 1860 .targetsize = sizeof(int), 1861 .family = NFPROTO_IPV6, 1862 #ifdef CONFIG_COMPAT 1863 .compatsize = sizeof(compat_int_t), 1864 .compat_from_user = compat_standard_from_user, 1865 .compat_to_user = compat_standard_to_user, 1866 #endif 1867 }, 1868 { 1869 .name = XT_ERROR_TARGET, 1870 .target = ip6t_error, 1871 .targetsize = XT_FUNCTION_MAXNAMELEN, 1872 .family = NFPROTO_IPV6, 1873 }, 1874 }; 1875 1876 static struct nf_sockopt_ops ip6t_sockopts = { 1877 .pf = PF_INET6, 1878 .set_optmin = IP6T_BASE_CTL, 1879 .set_optmax = IP6T_SO_SET_MAX+1, 1880 .set = do_ip6t_set_ctl, 1881 #ifdef CONFIG_COMPAT 1882 .compat_set = compat_do_ip6t_set_ctl, 1883 #endif 1884 .get_optmin = IP6T_BASE_CTL, 1885 .get_optmax = IP6T_SO_GET_MAX+1, 1886 .get = do_ip6t_get_ctl, 1887 #ifdef CONFIG_COMPAT 1888 .compat_get = compat_do_ip6t_get_ctl, 1889 #endif 1890 .owner = THIS_MODULE, 1891 }; 1892 1893 static struct xt_match ip6t_builtin_mt[] __read_mostly = { 1894 { 1895 .name = "icmp6", 1896 .match = icmp6_match, 1897 .matchsize = sizeof(struct ip6t_icmp), 1898 .checkentry = icmp6_checkentry, 1899 .proto = IPPROTO_ICMPV6, 1900 .family = NFPROTO_IPV6, 1901 }, 1902 }; 1903 1904 static int __net_init ip6_tables_net_init(struct net *net) 1905 { 1906 return xt_proto_init(net, NFPROTO_IPV6); 1907 } 1908 1909 static void __net_exit ip6_tables_net_exit(struct net *net) 1910 { 1911 xt_proto_fini(net, NFPROTO_IPV6); 1912 } 1913 1914 static struct pernet_operations ip6_tables_net_ops = { 1915 .init = ip6_tables_net_init, 1916 .exit = ip6_tables_net_exit, 1917 }; 1918 1919 static int __init ip6_tables_init(void) 1920 { 1921 int ret; 1922 1923 ret = register_pernet_subsys(&ip6_tables_net_ops); 1924 if (ret < 0) 1925 goto err1; 1926 1927 /* No one else will be downing sem now, so we won't sleep */ 1928 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1929 if (ret < 0) 1930 goto err2; 1931 ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1932 if (ret < 0) 1933 goto err4; 1934 1935 /* Register setsockopt */ 1936 ret = nf_register_sockopt(&ip6t_sockopts); 1937 if (ret < 0) 1938 goto err5; 1939 1940 pr_info("(C) 2000-2006 Netfilter Core Team\n"); 1941 return 0; 1942 1943 err5: 1944 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1945 err4: 1946 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1947 err2: 1948 unregister_pernet_subsys(&ip6_tables_net_ops); 1949 err1: 1950 return ret; 1951 } 1952 1953 static void __exit ip6_tables_fini(void) 1954 { 1955 nf_unregister_sockopt(&ip6t_sockopts); 1956 1957 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1958 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1959 unregister_pernet_subsys(&ip6_tables_net_ops); 1960 } 1961 1962 EXPORT_SYMBOL(ip6t_register_table); 1963 EXPORT_SYMBOL(ip6t_unregister_table); 1964 EXPORT_SYMBOL(ip6t_do_table); 1965 1966 module_init(ip6_tables_init); 1967 module_exit(ip6_tables_fini); 1968