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 <net/ipv6.h> 22 #include <net/compat.h> 23 #include <linux/uaccess.h> 24 #include <linux/mutex.h> 25 #include <linux/proc_fs.h> 26 #include <linux/err.h> 27 #include <linux/cpumask.h> 28 29 #include <linux/netfilter_ipv6/ip6_tables.h> 30 #include <linux/netfilter/x_tables.h> 31 #include <net/netfilter/nf_log.h> 32 #include "../../netfilter/xt_repldata.h" 33 34 MODULE_LICENSE("GPL"); 35 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 36 MODULE_DESCRIPTION("IPv6 packet filter"); 37 38 void *ip6t_alloc_initial_table(const struct xt_table *info) 39 { 40 return xt_alloc_initial_table(ip6t, IP6T); 41 } 42 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table); 43 44 /* Returns whether matches rule or not. */ 45 /* Performance critical - called for every packet */ 46 static inline bool 47 ip6_packet_match(const struct sk_buff *skb, 48 const char *indev, 49 const char *outdev, 50 const struct ip6t_ip6 *ip6info, 51 unsigned int *protoff, 52 u16 *fragoff, bool *hotdrop) 53 { 54 unsigned long ret; 55 const struct ipv6hdr *ipv6 = ipv6_hdr(skb); 56 57 if (NF_INVF(ip6info, IP6T_INV_SRCIP, 58 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, 59 &ip6info->src)) || 60 NF_INVF(ip6info, IP6T_INV_DSTIP, 61 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, 62 &ip6info->dst))) 63 return false; 64 65 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask); 66 67 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0)) 68 return false; 69 70 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask); 71 72 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0)) 73 return false; 74 75 /* ... might want to do something with class and flowlabel here ... */ 76 77 /* look for the desired protocol header */ 78 if (ip6info->flags & IP6T_F_PROTO) { 79 int protohdr; 80 unsigned short _frag_off; 81 82 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); 83 if (protohdr < 0) { 84 if (_frag_off == 0) 85 *hotdrop = true; 86 return false; 87 } 88 *fragoff = _frag_off; 89 90 if (ip6info->proto == protohdr) { 91 if (ip6info->invflags & IP6T_INV_PROTO) 92 return false; 93 94 return true; 95 } 96 97 /* We need match for the '-p all', too! */ 98 if ((ip6info->proto != 0) && 99 !(ip6info->invflags & IP6T_INV_PROTO)) 100 return false; 101 } 102 return true; 103 } 104 105 /* should be ip6 safe */ 106 static bool 107 ip6_checkentry(const struct ip6t_ip6 *ipv6) 108 { 109 if (ipv6->flags & ~IP6T_F_MASK) 110 return false; 111 if (ipv6->invflags & ~IP6T_INV_MASK) 112 return false; 113 114 return true; 115 } 116 117 static unsigned int 118 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par) 119 { 120 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 121 122 return NF_DROP; 123 } 124 125 static inline struct ip6t_entry * 126 get_entry(const void *base, unsigned int offset) 127 { 128 return (struct ip6t_entry *)(base + offset); 129 } 130 131 /* All zeroes == unconditional rule. */ 132 /* Mildly perf critical (only if packet tracing is on) */ 133 static inline bool unconditional(const struct ip6t_entry *e) 134 { 135 static const struct ip6t_ip6 uncond; 136 137 return e->target_offset == sizeof(struct ip6t_entry) && 138 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0; 139 } 140 141 static inline const struct xt_entry_target * 142 ip6t_get_target_c(const struct ip6t_entry *e) 143 { 144 return ip6t_get_target((struct ip6t_entry *)e); 145 } 146 147 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 148 /* This cries for unification! */ 149 static const char *const hooknames[] = { 150 [NF_INET_PRE_ROUTING] = "PREROUTING", 151 [NF_INET_LOCAL_IN] = "INPUT", 152 [NF_INET_FORWARD] = "FORWARD", 153 [NF_INET_LOCAL_OUT] = "OUTPUT", 154 [NF_INET_POST_ROUTING] = "POSTROUTING", 155 }; 156 157 enum nf_ip_trace_comments { 158 NF_IP6_TRACE_COMMENT_RULE, 159 NF_IP6_TRACE_COMMENT_RETURN, 160 NF_IP6_TRACE_COMMENT_POLICY, 161 }; 162 163 static const char *const comments[] = { 164 [NF_IP6_TRACE_COMMENT_RULE] = "rule", 165 [NF_IP6_TRACE_COMMENT_RETURN] = "return", 166 [NF_IP6_TRACE_COMMENT_POLICY] = "policy", 167 }; 168 169 static const struct nf_loginfo trace_loginfo = { 170 .type = NF_LOG_TYPE_LOG, 171 .u = { 172 .log = { 173 .level = LOGLEVEL_WARNING, 174 .logflags = NF_LOG_DEFAULT_MASK, 175 }, 176 }, 177 }; 178 179 /* Mildly perf critical (only if packet tracing is on) */ 180 static inline int 181 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e, 182 const char *hookname, const char **chainname, 183 const char **comment, unsigned int *rulenum) 184 { 185 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s); 186 187 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 188 /* Head of user chain: ERROR target with chainname */ 189 *chainname = t->target.data; 190 (*rulenum) = 0; 191 } else if (s == e) { 192 (*rulenum)++; 193 194 if (unconditional(s) && 195 strcmp(t->target.u.kernel.target->name, 196 XT_STANDARD_TARGET) == 0 && 197 t->verdict < 0) { 198 /* Tail of chains: STANDARD target (return/policy) */ 199 *comment = *chainname == hookname 200 ? comments[NF_IP6_TRACE_COMMENT_POLICY] 201 : comments[NF_IP6_TRACE_COMMENT_RETURN]; 202 } 203 return 1; 204 } else 205 (*rulenum)++; 206 207 return 0; 208 } 209 210 static void trace_packet(struct net *net, 211 const struct sk_buff *skb, 212 unsigned int hook, 213 const struct net_device *in, 214 const struct net_device *out, 215 const char *tablename, 216 const struct xt_table_info *private, 217 const struct ip6t_entry *e) 218 { 219 const struct ip6t_entry *root; 220 const char *hookname, *chainname, *comment; 221 const struct ip6t_entry *iter; 222 unsigned int rulenum = 0; 223 224 root = get_entry(private->entries, private->hook_entry[hook]); 225 226 hookname = chainname = hooknames[hook]; 227 comment = comments[NF_IP6_TRACE_COMMENT_RULE]; 228 229 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 230 if (get_chainname_rulenum(iter, e, hookname, 231 &chainname, &comment, &rulenum) != 0) 232 break; 233 234 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo, 235 "TRACE: %s:%s:%s:%u ", 236 tablename, chainname, comment, rulenum); 237 } 238 #endif 239 240 static inline struct ip6t_entry * 241 ip6t_next_entry(const struct ip6t_entry *entry) 242 { 243 return (void *)entry + entry->next_offset; 244 } 245 246 /* Returns one of the generic firewall policies, like NF_ACCEPT. */ 247 unsigned int 248 ip6t_do_table(void *priv, struct sk_buff *skb, 249 const struct nf_hook_state *state) 250 { 251 const struct xt_table *table = priv; 252 unsigned int hook = state->hook; 253 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 254 /* Initializing verdict to NF_DROP keeps gcc happy. */ 255 unsigned int verdict = NF_DROP; 256 const char *indev, *outdev; 257 const void *table_base; 258 struct ip6t_entry *e, **jumpstack; 259 unsigned int stackidx, cpu; 260 const struct xt_table_info *private; 261 struct xt_action_param acpar; 262 unsigned int addend; 263 264 /* Initialization */ 265 stackidx = 0; 266 indev = state->in ? state->in->name : nulldevname; 267 outdev = state->out ? state->out->name : nulldevname; 268 /* We handle fragments by dealing with the first fragment as 269 * if it was a normal packet. All other fragments are treated 270 * normally, except that they will NEVER match rules that ask 271 * things we don't know, ie. tcp syn flag or ports). If the 272 * rule is also a fragment-specific rule, non-fragments won't 273 * match it. */ 274 acpar.fragoff = 0; 275 acpar.hotdrop = false; 276 acpar.state = state; 277 278 WARN_ON(!(table->valid_hooks & (1 << hook))); 279 280 local_bh_disable(); 281 addend = xt_write_recseq_begin(); 282 private = READ_ONCE(table->private); /* Address dependency. */ 283 cpu = smp_processor_id(); 284 table_base = private->entries; 285 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 286 287 /* Switch to alternate jumpstack if we're being invoked via TEE. 288 * TEE issues XT_CONTINUE verdict on original skb so we must not 289 * clobber the jumpstack. 290 * 291 * For recursion via REJECT or SYNPROXY the stack will be clobbered 292 * but it is no problem since absolute verdict is issued by these. 293 */ 294 if (static_key_false(&xt_tee_enabled)) 295 jumpstack += private->stacksize * current->in_nf_duplicate; 296 297 e = get_entry(table_base, private->hook_entry[hook]); 298 299 do { 300 const struct xt_entry_target *t; 301 const struct xt_entry_match *ematch; 302 struct xt_counters *counter; 303 304 WARN_ON(!e); 305 acpar.thoff = 0; 306 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 307 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 308 no_match: 309 e = ip6t_next_entry(e); 310 continue; 311 } 312 313 xt_ematch_foreach(ematch, e) { 314 acpar.match = ematch->u.kernel.match; 315 acpar.matchinfo = ematch->data; 316 if (!acpar.match->match(skb, &acpar)) 317 goto no_match; 318 } 319 320 counter = xt_get_this_cpu_counter(&e->counters); 321 ADD_COUNTER(*counter, skb->len, 1); 322 323 t = ip6t_get_target_c(e); 324 WARN_ON(!t->u.kernel.target); 325 326 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 327 /* The packet is traced: log it */ 328 if (unlikely(skb->nf_trace)) 329 trace_packet(state->net, skb, hook, state->in, 330 state->out, table->name, private, e); 331 #endif 332 /* Standard target? */ 333 if (!t->u.kernel.target->target) { 334 int v; 335 336 v = ((struct xt_standard_target *)t)->verdict; 337 if (v < 0) { 338 /* Pop from stack? */ 339 if (v != XT_RETURN) { 340 verdict = (unsigned int)(-v) - 1; 341 break; 342 } 343 if (stackidx == 0) 344 e = get_entry(table_base, 345 private->underflow[hook]); 346 else 347 e = ip6t_next_entry(jumpstack[--stackidx]); 348 continue; 349 } 350 if (table_base + v != ip6t_next_entry(e) && 351 !(e->ipv6.flags & IP6T_F_GOTO)) { 352 if (unlikely(stackidx >= private->stacksize)) { 353 verdict = NF_DROP; 354 break; 355 } 356 jumpstack[stackidx++] = e; 357 } 358 359 e = get_entry(table_base, v); 360 continue; 361 } 362 363 acpar.target = t->u.kernel.target; 364 acpar.targinfo = t->data; 365 366 verdict = t->u.kernel.target->target(skb, &acpar); 367 if (verdict == XT_CONTINUE) 368 e = ip6t_next_entry(e); 369 else 370 /* Verdict */ 371 break; 372 } while (!acpar.hotdrop); 373 374 xt_write_recseq_end(addend); 375 local_bh_enable(); 376 377 if (acpar.hotdrop) 378 return NF_DROP; 379 else return verdict; 380 } 381 382 /* Figures out from what hook each rule can be called: returns 0 if 383 there are loops. Puts hook bitmask in comefrom. */ 384 static int 385 mark_source_chains(const struct xt_table_info *newinfo, 386 unsigned int valid_hooks, void *entry0, 387 unsigned int *offsets) 388 { 389 unsigned int hook; 390 391 /* No recursion; use packet counter to save back ptrs (reset 392 to 0 as we leave), and comefrom to save source hook bitmask */ 393 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 394 unsigned int pos = newinfo->hook_entry[hook]; 395 struct ip6t_entry *e = entry0 + pos; 396 397 if (!(valid_hooks & (1 << hook))) 398 continue; 399 400 /* Set initial back pointer. */ 401 e->counters.pcnt = pos; 402 403 for (;;) { 404 const struct xt_standard_target *t 405 = (void *)ip6t_get_target_c(e); 406 int visited = e->comefrom & (1 << hook); 407 408 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 409 return 0; 410 411 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 412 413 /* Unconditional return/END. */ 414 if ((unconditional(e) && 415 (strcmp(t->target.u.user.name, 416 XT_STANDARD_TARGET) == 0) && 417 t->verdict < 0) || visited) { 418 unsigned int oldpos, size; 419 420 /* Return: backtrack through the last 421 big jump. */ 422 do { 423 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 424 oldpos = pos; 425 pos = e->counters.pcnt; 426 e->counters.pcnt = 0; 427 428 /* We're at the start. */ 429 if (pos == oldpos) 430 goto next; 431 432 e = entry0 + pos; 433 } while (oldpos == pos + e->next_offset); 434 435 /* Move along one */ 436 size = e->next_offset; 437 e = entry0 + pos + size; 438 if (pos + size >= newinfo->size) 439 return 0; 440 e->counters.pcnt = pos; 441 pos += size; 442 } else { 443 int newpos = t->verdict; 444 445 if (strcmp(t->target.u.user.name, 446 XT_STANDARD_TARGET) == 0 && 447 newpos >= 0) { 448 /* This a jump; chase it. */ 449 if (!xt_find_jump_offset(offsets, newpos, 450 newinfo->number)) 451 return 0; 452 } else { 453 /* ... this is a fallthru */ 454 newpos = pos + e->next_offset; 455 if (newpos >= newinfo->size) 456 return 0; 457 } 458 e = entry0 + newpos; 459 e->counters.pcnt = pos; 460 pos = newpos; 461 } 462 } 463 next: ; 464 } 465 return 1; 466 } 467 468 static void cleanup_match(struct xt_entry_match *m, struct net *net) 469 { 470 struct xt_mtdtor_param par; 471 472 par.net = net; 473 par.match = m->u.kernel.match; 474 par.matchinfo = m->data; 475 par.family = NFPROTO_IPV6; 476 if (par.match->destroy != NULL) 477 par.match->destroy(&par); 478 module_put(par.match->me); 479 } 480 481 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 482 { 483 const struct ip6t_ip6 *ipv6 = par->entryinfo; 484 485 par->match = m->u.kernel.match; 486 par->matchinfo = m->data; 487 488 return xt_check_match(par, m->u.match_size - sizeof(*m), 489 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 490 } 491 492 static int 493 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 494 { 495 struct xt_match *match; 496 int ret; 497 498 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 499 m->u.user.revision); 500 if (IS_ERR(match)) 501 return PTR_ERR(match); 502 503 m->u.kernel.match = match; 504 505 ret = check_match(m, par); 506 if (ret) 507 goto err; 508 509 return 0; 510 err: 511 module_put(m->u.kernel.match->me); 512 return ret; 513 } 514 515 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 516 { 517 struct xt_entry_target *t = ip6t_get_target(e); 518 struct xt_tgchk_param par = { 519 .net = net, 520 .table = name, 521 .entryinfo = e, 522 .target = t->u.kernel.target, 523 .targinfo = t->data, 524 .hook_mask = e->comefrom, 525 .family = NFPROTO_IPV6, 526 }; 527 528 return xt_check_target(&par, t->u.target_size - sizeof(*t), 529 e->ipv6.proto, 530 e->ipv6.invflags & IP6T_INV_PROTO); 531 } 532 533 static int 534 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 535 unsigned int size, 536 struct xt_percpu_counter_alloc_state *alloc_state) 537 { 538 struct xt_entry_target *t; 539 struct xt_target *target; 540 int ret; 541 unsigned int j; 542 struct xt_mtchk_param mtpar; 543 struct xt_entry_match *ematch; 544 545 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 546 return -ENOMEM; 547 548 j = 0; 549 memset(&mtpar, 0, sizeof(mtpar)); 550 mtpar.net = net; 551 mtpar.table = name; 552 mtpar.entryinfo = &e->ipv6; 553 mtpar.hook_mask = e->comefrom; 554 mtpar.family = NFPROTO_IPV6; 555 xt_ematch_foreach(ematch, e) { 556 ret = find_check_match(ematch, &mtpar); 557 if (ret != 0) 558 goto cleanup_matches; 559 ++j; 560 } 561 562 t = ip6t_get_target(e); 563 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 564 t->u.user.revision); 565 if (IS_ERR(target)) { 566 ret = PTR_ERR(target); 567 goto cleanup_matches; 568 } 569 t->u.kernel.target = target; 570 571 ret = check_target(e, net, name); 572 if (ret) 573 goto err; 574 return 0; 575 err: 576 module_put(t->u.kernel.target->me); 577 cleanup_matches: 578 xt_ematch_foreach(ematch, e) { 579 if (j-- == 0) 580 break; 581 cleanup_match(ematch, net); 582 } 583 584 xt_percpu_counter_free(&e->counters); 585 586 return ret; 587 } 588 589 static bool check_underflow(const struct ip6t_entry *e) 590 { 591 const struct xt_entry_target *t; 592 unsigned int verdict; 593 594 if (!unconditional(e)) 595 return false; 596 t = ip6t_get_target_c(e); 597 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 598 return false; 599 verdict = ((struct xt_standard_target *)t)->verdict; 600 verdict = -verdict - 1; 601 return verdict == NF_DROP || verdict == NF_ACCEPT; 602 } 603 604 static int 605 check_entry_size_and_hooks(struct ip6t_entry *e, 606 struct xt_table_info *newinfo, 607 const unsigned char *base, 608 const unsigned char *limit, 609 const unsigned int *hook_entries, 610 const unsigned int *underflows, 611 unsigned int valid_hooks) 612 { 613 unsigned int h; 614 int err; 615 616 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 617 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 618 (unsigned char *)e + e->next_offset > limit) 619 return -EINVAL; 620 621 if (e->next_offset 622 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 623 return -EINVAL; 624 625 if (!ip6_checkentry(&e->ipv6)) 626 return -EINVAL; 627 628 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 629 e->next_offset); 630 if (err) 631 return err; 632 633 /* Check hooks & underflows */ 634 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 635 if (!(valid_hooks & (1 << h))) 636 continue; 637 if ((unsigned char *)e - base == hook_entries[h]) 638 newinfo->hook_entry[h] = hook_entries[h]; 639 if ((unsigned char *)e - base == underflows[h]) { 640 if (!check_underflow(e)) 641 return -EINVAL; 642 643 newinfo->underflow[h] = underflows[h]; 644 } 645 } 646 647 /* Clear counters and comefrom */ 648 e->counters = ((struct xt_counters) { 0, 0 }); 649 e->comefrom = 0; 650 return 0; 651 } 652 653 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 654 { 655 struct xt_tgdtor_param par; 656 struct xt_entry_target *t; 657 struct xt_entry_match *ematch; 658 659 /* Cleanup all matches */ 660 xt_ematch_foreach(ematch, e) 661 cleanup_match(ematch, net); 662 t = ip6t_get_target(e); 663 664 par.net = net; 665 par.target = t->u.kernel.target; 666 par.targinfo = t->data; 667 par.family = NFPROTO_IPV6; 668 if (par.target->destroy != NULL) 669 par.target->destroy(&par); 670 module_put(par.target->me); 671 xt_percpu_counter_free(&e->counters); 672 } 673 674 /* Checks and translates the user-supplied table segment (held in 675 newinfo) */ 676 static int 677 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 678 const struct ip6t_replace *repl) 679 { 680 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 681 struct ip6t_entry *iter; 682 unsigned int *offsets; 683 unsigned int i; 684 int ret = 0; 685 686 newinfo->size = repl->size; 687 newinfo->number = repl->num_entries; 688 689 /* Init all hooks to impossible value. */ 690 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 691 newinfo->hook_entry[i] = 0xFFFFFFFF; 692 newinfo->underflow[i] = 0xFFFFFFFF; 693 } 694 695 offsets = xt_alloc_entry_offsets(newinfo->number); 696 if (!offsets) 697 return -ENOMEM; 698 i = 0; 699 /* Walk through entries, checking offsets. */ 700 xt_entry_foreach(iter, entry0, newinfo->size) { 701 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 702 entry0 + repl->size, 703 repl->hook_entry, 704 repl->underflow, 705 repl->valid_hooks); 706 if (ret != 0) 707 goto out_free; 708 if (i < repl->num_entries) 709 offsets[i] = (void *)iter - entry0; 710 ++i; 711 if (strcmp(ip6t_get_target(iter)->u.user.name, 712 XT_ERROR_TARGET) == 0) 713 ++newinfo->stacksize; 714 } 715 716 ret = -EINVAL; 717 if (i != repl->num_entries) 718 goto out_free; 719 720 ret = xt_check_table_hooks(newinfo, repl->valid_hooks); 721 if (ret) 722 goto out_free; 723 724 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 725 ret = -ELOOP; 726 goto out_free; 727 } 728 kvfree(offsets); 729 730 /* Finally, each sanity check must pass */ 731 i = 0; 732 xt_entry_foreach(iter, entry0, newinfo->size) { 733 ret = find_check_entry(iter, net, repl->name, repl->size, 734 &alloc_state); 735 if (ret != 0) 736 break; 737 ++i; 738 } 739 740 if (ret != 0) { 741 xt_entry_foreach(iter, entry0, newinfo->size) { 742 if (i-- == 0) 743 break; 744 cleanup_entry(iter, net); 745 } 746 return ret; 747 } 748 749 return ret; 750 out_free: 751 kvfree(offsets); 752 return ret; 753 } 754 755 static void 756 get_counters(const struct xt_table_info *t, 757 struct xt_counters counters[]) 758 { 759 struct ip6t_entry *iter; 760 unsigned int cpu; 761 unsigned int i; 762 763 for_each_possible_cpu(cpu) { 764 seqcount_t *s = &per_cpu(xt_recseq, cpu); 765 766 i = 0; 767 xt_entry_foreach(iter, t->entries, t->size) { 768 struct xt_counters *tmp; 769 u64 bcnt, pcnt; 770 unsigned int start; 771 772 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 773 do { 774 start = read_seqcount_begin(s); 775 bcnt = tmp->bcnt; 776 pcnt = tmp->pcnt; 777 } while (read_seqcount_retry(s, start)); 778 779 ADD_COUNTER(counters[i], bcnt, pcnt); 780 ++i; 781 cond_resched(); 782 } 783 } 784 } 785 786 static void get_old_counters(const struct xt_table_info *t, 787 struct xt_counters counters[]) 788 { 789 struct ip6t_entry *iter; 790 unsigned int cpu, i; 791 792 for_each_possible_cpu(cpu) { 793 i = 0; 794 xt_entry_foreach(iter, t->entries, t->size) { 795 const struct xt_counters *tmp; 796 797 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 798 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 799 ++i; 800 } 801 cond_resched(); 802 } 803 } 804 805 static struct xt_counters *alloc_counters(const struct xt_table *table) 806 { 807 unsigned int countersize; 808 struct xt_counters *counters; 809 const struct xt_table_info *private = table->private; 810 811 /* We need atomic snapshot of counters: rest doesn't change 812 (other than comefrom, which userspace doesn't care 813 about). */ 814 countersize = sizeof(struct xt_counters) * private->number; 815 counters = vzalloc(countersize); 816 817 if (counters == NULL) 818 return ERR_PTR(-ENOMEM); 819 820 get_counters(private, counters); 821 822 return counters; 823 } 824 825 static int 826 copy_entries_to_user(unsigned int total_size, 827 const struct xt_table *table, 828 void __user *userptr) 829 { 830 unsigned int off, num; 831 const struct ip6t_entry *e; 832 struct xt_counters *counters; 833 const struct xt_table_info *private = table->private; 834 int ret = 0; 835 const void *loc_cpu_entry; 836 837 counters = alloc_counters(table); 838 if (IS_ERR(counters)) 839 return PTR_ERR(counters); 840 841 loc_cpu_entry = private->entries; 842 843 /* FIXME: use iterator macros --RR */ 844 /* ... then go back and fix counters and names */ 845 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 846 unsigned int i; 847 const struct xt_entry_match *m; 848 const struct xt_entry_target *t; 849 850 e = loc_cpu_entry + off; 851 if (copy_to_user(userptr + off, e, 852 offsetof(struct ip6t_entry, counters)) || 853 copy_to_user(userptr + off 854 + offsetof(struct ip6t_entry, counters), 855 &counters[num], 856 sizeof(counters[num]))) { 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_NETFILTER_XTABLES_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 ret = xt_compat_init_offsets(AF_INET6, info->number); 949 if (ret) 950 return ret; 951 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 952 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 953 if (ret != 0) 954 return ret; 955 } 956 return 0; 957 } 958 #endif 959 960 static int get_info(struct net *net, void __user *user, const int *len) 961 { 962 char name[XT_TABLE_MAXNAMELEN]; 963 struct xt_table *t; 964 int ret; 965 966 if (*len != sizeof(struct ip6t_getinfo)) 967 return -EINVAL; 968 969 if (copy_from_user(name, user, sizeof(name)) != 0) 970 return -EFAULT; 971 972 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 973 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 974 if (in_compat_syscall()) 975 xt_compat_lock(AF_INET6); 976 #endif 977 t = xt_request_find_table_lock(net, AF_INET6, name); 978 if (!IS_ERR(t)) { 979 struct ip6t_getinfo info; 980 const struct xt_table_info *private = t->private; 981 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 982 struct xt_table_info tmp; 983 984 if (in_compat_syscall()) { 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 = PTR_ERR(t); 1009 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1010 if (in_compat_syscall()) 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 (!IS_ERR(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 = PTR_ERR(t); 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 counters = xt_counters_alloc(num_counters); 1062 if (!counters) { 1063 ret = -ENOMEM; 1064 goto out; 1065 } 1066 1067 t = xt_request_find_table_lock(net, AF_INET6, name); 1068 if (IS_ERR(t)) { 1069 ret = PTR_ERR(t); 1070 goto free_newinfo_counters_untrans; 1071 } 1072 1073 /* You lied! */ 1074 if (valid_hooks != t->valid_hooks) { 1075 ret = -EINVAL; 1076 goto put_module; 1077 } 1078 1079 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1080 if (!oldinfo) 1081 goto put_module; 1082 1083 /* Update module usage count based on number of rules */ 1084 if ((oldinfo->number > oldinfo->initial_entries) || 1085 (newinfo->number <= oldinfo->initial_entries)) 1086 module_put(t->me); 1087 if ((oldinfo->number > oldinfo->initial_entries) && 1088 (newinfo->number <= oldinfo->initial_entries)) 1089 module_put(t->me); 1090 1091 xt_table_unlock(t); 1092 1093 get_old_counters(oldinfo, counters); 1094 1095 /* Decrease module usage counts and free resource */ 1096 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1097 cleanup_entry(iter, net); 1098 1099 xt_free_table_info(oldinfo); 1100 if (copy_to_user(counters_ptr, counters, 1101 sizeof(struct xt_counters) * num_counters) != 0) { 1102 /* Silent error, can't fail, new table is already in place */ 1103 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1104 } 1105 vfree(counters); 1106 return 0; 1107 1108 put_module: 1109 module_put(t->me); 1110 xt_table_unlock(t); 1111 free_newinfo_counters_untrans: 1112 vfree(counters); 1113 out: 1114 return ret; 1115 } 1116 1117 static int 1118 do_replace(struct net *net, sockptr_t arg, unsigned int len) 1119 { 1120 int ret; 1121 struct ip6t_replace tmp; 1122 struct xt_table_info *newinfo; 1123 void *loc_cpu_entry; 1124 struct ip6t_entry *iter; 1125 1126 if (len < sizeof(tmp)) 1127 return -EINVAL; 1128 if (copy_from_sockptr(&tmp, arg, 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 if ((u64)len < (u64)tmp.size + sizeof(tmp)) 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 = t->private; 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_NETFILTER_XTABLES_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, offsetof(struct compat_ip6t_entry, counters)) || 1246 copy_to_user(&ce->counters, &counters[i], sizeof(counters[i]))) 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; 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 ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries); 1424 if (ret) 1425 goto out_unlock; 1426 /* Walk through entries, checking offsets. */ 1427 xt_entry_foreach(iter0, entry0, compatr->size) { 1428 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1429 entry0, 1430 entry0 + compatr->size); 1431 if (ret != 0) 1432 goto out_unlock; 1433 ++j; 1434 } 1435 1436 ret = -EINVAL; 1437 if (j != compatr->num_entries) 1438 goto out_unlock; 1439 1440 ret = -ENOMEM; 1441 newinfo = xt_alloc_table_info(size); 1442 if (!newinfo) 1443 goto out_unlock; 1444 1445 memset(newinfo->entries, 0, size); 1446 1447 newinfo->number = compatr->num_entries; 1448 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1449 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1450 newinfo->underflow[i] = compatr->underflow[i]; 1451 } 1452 entry1 = newinfo->entries; 1453 pos = entry1; 1454 size = compatr->size; 1455 xt_entry_foreach(iter0, entry0, compatr->size) 1456 compat_copy_entry_from_user(iter0, &pos, &size, 1457 newinfo, entry1); 1458 1459 /* all module references in entry0 are now gone. */ 1460 xt_compat_flush_offsets(AF_INET6); 1461 xt_compat_unlock(AF_INET6); 1462 1463 memcpy(&repl, compatr, sizeof(*compatr)); 1464 1465 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1466 repl.hook_entry[i] = newinfo->hook_entry[i]; 1467 repl.underflow[i] = newinfo->underflow[i]; 1468 } 1469 1470 repl.num_counters = 0; 1471 repl.counters = NULL; 1472 repl.size = newinfo->size; 1473 ret = translate_table(net, newinfo, entry1, &repl); 1474 if (ret) 1475 goto free_newinfo; 1476 1477 *pinfo = newinfo; 1478 *pentry0 = entry1; 1479 xt_free_table_info(info); 1480 return 0; 1481 1482 free_newinfo: 1483 xt_free_table_info(newinfo); 1484 return ret; 1485 out_unlock: 1486 xt_compat_flush_offsets(AF_INET6); 1487 xt_compat_unlock(AF_INET6); 1488 xt_entry_foreach(iter0, entry0, compatr->size) { 1489 if (j-- == 0) 1490 break; 1491 compat_release_entry(iter0); 1492 } 1493 return ret; 1494 } 1495 1496 static int 1497 compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) 1498 { 1499 int ret; 1500 struct compat_ip6t_replace tmp; 1501 struct xt_table_info *newinfo; 1502 void *loc_cpu_entry; 1503 struct ip6t_entry *iter; 1504 1505 if (len < sizeof(tmp)) 1506 return -EINVAL; 1507 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1508 return -EFAULT; 1509 1510 /* overflow check */ 1511 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1512 return -ENOMEM; 1513 if (tmp.num_counters == 0) 1514 return -EINVAL; 1515 if ((u64)len < (u64)tmp.size + sizeof(tmp)) 1516 return -EINVAL; 1517 1518 tmp.name[sizeof(tmp.name)-1] = 0; 1519 1520 newinfo = xt_alloc_table_info(tmp.size); 1521 if (!newinfo) 1522 return -ENOMEM; 1523 1524 loc_cpu_entry = newinfo->entries; 1525 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1526 tmp.size) != 0) { 1527 ret = -EFAULT; 1528 goto free_newinfo; 1529 } 1530 1531 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1532 if (ret != 0) 1533 goto free_newinfo; 1534 1535 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1536 tmp.num_counters, compat_ptr(tmp.counters)); 1537 if (ret) 1538 goto free_newinfo_untrans; 1539 return 0; 1540 1541 free_newinfo_untrans: 1542 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1543 cleanup_entry(iter, net); 1544 free_newinfo: 1545 xt_free_table_info(newinfo); 1546 return ret; 1547 } 1548 1549 struct compat_ip6t_get_entries { 1550 char name[XT_TABLE_MAXNAMELEN]; 1551 compat_uint_t size; 1552 struct compat_ip6t_entry entrytable[]; 1553 }; 1554 1555 static int 1556 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1557 void __user *userptr) 1558 { 1559 struct xt_counters *counters; 1560 const struct xt_table_info *private = table->private; 1561 void __user *pos; 1562 unsigned int size; 1563 int ret = 0; 1564 unsigned int i = 0; 1565 struct ip6t_entry *iter; 1566 1567 counters = alloc_counters(table); 1568 if (IS_ERR(counters)) 1569 return PTR_ERR(counters); 1570 1571 pos = userptr; 1572 size = total_size; 1573 xt_entry_foreach(iter, private->entries, total_size) { 1574 ret = compat_copy_entry_to_user(iter, &pos, 1575 &size, counters, i++); 1576 if (ret != 0) 1577 break; 1578 } 1579 1580 vfree(counters); 1581 return ret; 1582 } 1583 1584 static int 1585 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1586 int *len) 1587 { 1588 int ret; 1589 struct compat_ip6t_get_entries get; 1590 struct xt_table *t; 1591 1592 if (*len < sizeof(get)) 1593 return -EINVAL; 1594 1595 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1596 return -EFAULT; 1597 1598 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1599 return -EINVAL; 1600 1601 get.name[sizeof(get.name) - 1] = '\0'; 1602 1603 xt_compat_lock(AF_INET6); 1604 t = xt_find_table_lock(net, AF_INET6, get.name); 1605 if (!IS_ERR(t)) { 1606 const struct xt_table_info *private = t->private; 1607 struct xt_table_info info; 1608 ret = compat_table_info(private, &info); 1609 if (!ret && get.size == info.size) 1610 ret = compat_copy_entries_to_user(private->size, 1611 t, uptr->entrytable); 1612 else if (!ret) 1613 ret = -EAGAIN; 1614 1615 xt_compat_flush_offsets(AF_INET6); 1616 module_put(t->me); 1617 xt_table_unlock(t); 1618 } else 1619 ret = PTR_ERR(t); 1620 1621 xt_compat_unlock(AF_INET6); 1622 return ret; 1623 } 1624 #endif 1625 1626 static int 1627 do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len) 1628 { 1629 int ret; 1630 1631 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1632 return -EPERM; 1633 if (!xt_compat_check()) 1634 return -EPERM; 1635 1636 switch (cmd) { 1637 case IP6T_SO_SET_REPLACE: 1638 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1639 if (in_compat_syscall()) 1640 ret = compat_do_replace(sock_net(sk), arg, len); 1641 else 1642 #endif 1643 ret = do_replace(sock_net(sk), arg, len); 1644 break; 1645 1646 case IP6T_SO_SET_ADD_COUNTERS: 1647 ret = do_add_counters(sock_net(sk), arg, len); 1648 break; 1649 1650 default: 1651 ret = -EINVAL; 1652 } 1653 1654 return ret; 1655 } 1656 1657 static int 1658 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1659 { 1660 int ret; 1661 1662 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1663 return -EPERM; 1664 if (!xt_compat_check()) 1665 return -EPERM; 1666 1667 switch (cmd) { 1668 case IP6T_SO_GET_INFO: 1669 ret = get_info(sock_net(sk), user, len); 1670 break; 1671 1672 case IP6T_SO_GET_ENTRIES: 1673 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1674 if (in_compat_syscall()) 1675 ret = compat_get_entries(sock_net(sk), user, len); 1676 else 1677 #endif 1678 ret = get_entries(sock_net(sk), user, len); 1679 break; 1680 1681 case IP6T_SO_GET_REVISION_MATCH: 1682 case IP6T_SO_GET_REVISION_TARGET: { 1683 struct xt_get_revision rev; 1684 int target; 1685 1686 if (*len != sizeof(rev)) { 1687 ret = -EINVAL; 1688 break; 1689 } 1690 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1691 ret = -EFAULT; 1692 break; 1693 } 1694 rev.name[sizeof(rev.name)-1] = 0; 1695 1696 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1697 target = 1; 1698 else 1699 target = 0; 1700 1701 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1702 rev.revision, 1703 target, &ret), 1704 "ip6t_%s", rev.name); 1705 break; 1706 } 1707 1708 default: 1709 ret = -EINVAL; 1710 } 1711 1712 return ret; 1713 } 1714 1715 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1716 { 1717 struct xt_table_info *private = table->private; 1718 struct module *table_owner = table->me; 1719 struct ip6t_entry *iter; 1720 void *loc_cpu_entry; 1721 1722 /* Decrease module usage counts and free resources */ 1723 loc_cpu_entry = private->entries; 1724 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1725 cleanup_entry(iter, net); 1726 if (private->number > private->initial_entries) 1727 module_put(table_owner); 1728 xt_free_table_info(private); 1729 kfree(table); 1730 } 1731 1732 int ip6t_register_table(struct net *net, const struct xt_table *table, 1733 const struct ip6t_replace *repl, 1734 const struct nf_hook_ops *template_ops) 1735 { 1736 struct xt_table_info bootstrap = {0}; 1737 struct xt_table_info *newinfo; 1738 struct xt_table *new_table; 1739 void *loc_cpu_entry; 1740 int ret; 1741 1742 newinfo = xt_alloc_table_info(repl->size); 1743 if (!newinfo) 1744 return -ENOMEM; 1745 1746 loc_cpu_entry = newinfo->entries; 1747 memcpy(loc_cpu_entry, repl->entries, repl->size); 1748 1749 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1750 if (ret != 0) { 1751 xt_free_table_info(newinfo); 1752 return ret; 1753 } 1754 1755 new_table = xt_register_table(net, table, template_ops, &bootstrap, newinfo); 1756 if (IS_ERR(new_table)) { 1757 struct ip6t_entry *iter; 1758 1759 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1760 cleanup_entry(iter, net); 1761 xt_free_table_info(newinfo); 1762 return PTR_ERR(new_table); 1763 } 1764 1765 return ret; 1766 } 1767 1768 void ip6t_unregister_table_exit(struct net *net, const char *name) 1769 { 1770 struct xt_table *table = xt_unregister_table_exit(net, NFPROTO_IPV6, name); 1771 1772 if (table) 1773 __ip6t_unregister_table(net, table); 1774 } 1775 1776 /* The built-in targets: standard (NULL) and error. */ 1777 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1778 { 1779 .name = XT_STANDARD_TARGET, 1780 .targetsize = sizeof(int), 1781 .family = NFPROTO_IPV6, 1782 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1783 .compatsize = sizeof(compat_int_t), 1784 .compat_from_user = compat_standard_from_user, 1785 .compat_to_user = compat_standard_to_user, 1786 #endif 1787 }, 1788 { 1789 .name = XT_ERROR_TARGET, 1790 .target = ip6t_error, 1791 .targetsize = XT_FUNCTION_MAXNAMELEN, 1792 .family = NFPROTO_IPV6, 1793 }, 1794 }; 1795 1796 static struct nf_sockopt_ops ip6t_sockopts = { 1797 .pf = PF_INET6, 1798 .set_optmin = IP6T_BASE_CTL, 1799 .set_optmax = IP6T_SO_SET_MAX+1, 1800 .set = do_ip6t_set_ctl, 1801 .get_optmin = IP6T_BASE_CTL, 1802 .get_optmax = IP6T_SO_GET_MAX+1, 1803 .get = do_ip6t_get_ctl, 1804 .owner = THIS_MODULE, 1805 }; 1806 1807 static int __net_init ip6_tables_net_init(struct net *net) 1808 { 1809 return xt_proto_init(net, NFPROTO_IPV6); 1810 } 1811 1812 static void __net_exit ip6_tables_net_exit(struct net *net) 1813 { 1814 xt_proto_fini(net, NFPROTO_IPV6); 1815 } 1816 1817 static struct pernet_operations ip6_tables_net_ops = { 1818 .init = ip6_tables_net_init, 1819 .exit = ip6_tables_net_exit, 1820 }; 1821 1822 static int __init ip6_tables_init(void) 1823 { 1824 int ret; 1825 1826 ret = register_pernet_subsys(&ip6_tables_net_ops); 1827 if (ret < 0) 1828 goto err1; 1829 1830 /* No one else will be downing sem now, so we won't sleep */ 1831 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1832 if (ret < 0) 1833 goto err2; 1834 1835 /* Register setsockopt */ 1836 ret = nf_register_sockopt(&ip6t_sockopts); 1837 if (ret < 0) 1838 goto err4; 1839 1840 return 0; 1841 1842 err4: 1843 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1844 err2: 1845 unregister_pernet_subsys(&ip6_tables_net_ops); 1846 err1: 1847 return ret; 1848 } 1849 1850 static void __exit ip6_tables_fini(void) 1851 { 1852 nf_unregister_sockopt(&ip6t_sockopts); 1853 1854 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1855 unregister_pernet_subsys(&ip6_tables_net_ops); 1856 } 1857 1858 EXPORT_SYMBOL(ip6t_register_table); 1859 EXPORT_SYMBOL(ip6t_unregister_table_exit); 1860 EXPORT_SYMBOL(ip6t_do_table); 1861 1862 module_init(ip6_tables_init); 1863 module_exit(ip6_tables_fini); 1864