1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org> 4 * 5 * This software has been sponsored by Sophos Astaro <http://www.sophos.com> 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/init.h> 10 #include <linux/module.h> 11 #include <linux/netlink.h> 12 #include <linux/netfilter.h> 13 #include <linux/netfilter/nfnetlink.h> 14 #include <linux/netfilter/nf_tables.h> 15 #include <linux/netfilter/nf_tables_compat.h> 16 #include <linux/netfilter/x_tables.h> 17 #include <linux/netfilter_ipv4/ip_tables.h> 18 #include <linux/netfilter_ipv6/ip6_tables.h> 19 #include <linux/netfilter_bridge/ebtables.h> 20 #include <linux/netfilter_arp/arp_tables.h> 21 #include <net/netfilter/nf_tables.h> 22 #include <net/netfilter/nf_log.h> 23 24 /* Used for matches where *info is larger than X byte */ 25 #define NFT_MATCH_LARGE_THRESH 192 26 27 struct nft_xt_match_priv { 28 void *info; 29 }; 30 31 static int nft_compat_chain_validate_dependency(const struct nft_ctx *ctx, 32 const char *tablename) 33 { 34 enum nft_chain_types type = NFT_CHAIN_T_DEFAULT; 35 const struct nft_chain *chain = ctx->chain; 36 const struct nft_base_chain *basechain; 37 38 if (!tablename || 39 !nft_is_base_chain(chain)) 40 return 0; 41 42 basechain = nft_base_chain(chain); 43 if (strcmp(tablename, "nat") == 0) { 44 if (ctx->family != NFPROTO_BRIDGE) 45 type = NFT_CHAIN_T_NAT; 46 if (basechain->type->type != type) 47 return -EINVAL; 48 } 49 50 return 0; 51 } 52 53 union nft_entry { 54 struct ipt_entry e4; 55 struct ip6t_entry e6; 56 struct ebt_entry ebt; 57 struct arpt_entry arp; 58 }; 59 60 static inline void 61 nft_compat_set_par(struct xt_action_param *par, 62 const struct nft_pktinfo *pkt, 63 const void *xt, const void *xt_info) 64 { 65 par->state = pkt->state; 66 par->thoff = nft_thoff(pkt); 67 par->fragoff = pkt->fragoff; 68 par->target = xt; 69 par->targinfo = xt_info; 70 par->hotdrop = false; 71 } 72 73 static void nft_target_eval_xt(const struct nft_expr *expr, 74 struct nft_regs *regs, 75 const struct nft_pktinfo *pkt) 76 { 77 void *info = nft_expr_priv(expr); 78 struct xt_target *target = expr->ops->data; 79 struct sk_buff *skb = pkt->skb; 80 struct xt_action_param xt; 81 int ret; 82 83 nft_compat_set_par(&xt, pkt, target, info); 84 85 ret = target->target(skb, &xt); 86 87 if (xt.hotdrop) 88 ret = NF_DROP; 89 90 switch (ret) { 91 case XT_CONTINUE: 92 regs->verdict.code = NFT_CONTINUE; 93 break; 94 default: 95 regs->verdict.code = ret; 96 break; 97 } 98 } 99 100 static void nft_target_eval_bridge(const struct nft_expr *expr, 101 struct nft_regs *regs, 102 const struct nft_pktinfo *pkt) 103 { 104 void *info = nft_expr_priv(expr); 105 struct xt_target *target = expr->ops->data; 106 struct sk_buff *skb = pkt->skb; 107 struct xt_action_param xt; 108 int ret; 109 110 nft_compat_set_par(&xt, pkt, target, info); 111 112 ret = target->target(skb, &xt); 113 114 if (xt.hotdrop) 115 ret = NF_DROP; 116 117 switch (ret) { 118 case EBT_ACCEPT: 119 regs->verdict.code = NF_ACCEPT; 120 break; 121 case EBT_DROP: 122 regs->verdict.code = NF_DROP; 123 break; 124 case EBT_CONTINUE: 125 regs->verdict.code = NFT_CONTINUE; 126 break; 127 case EBT_RETURN: 128 regs->verdict.code = NFT_RETURN; 129 break; 130 default: 131 regs->verdict.code = ret; 132 break; 133 } 134 } 135 136 static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = { 137 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING }, 138 [NFTA_TARGET_REV] = NLA_POLICY_MAX(NLA_BE32, 255), 139 [NFTA_TARGET_INFO] = { .type = NLA_BINARY }, 140 }; 141 142 static void 143 nft_target_set_tgchk_param(struct xt_tgchk_param *par, 144 const struct nft_ctx *ctx, 145 struct xt_target *target, void *info, 146 union nft_entry *entry, u16 proto, bool inv) 147 { 148 par->net = ctx->net; 149 par->table = ctx->table->name; 150 switch (ctx->family) { 151 case AF_INET: 152 entry->e4.ip.proto = proto; 153 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; 154 break; 155 case AF_INET6: 156 if (proto) 157 entry->e6.ipv6.flags |= IP6T_F_PROTO; 158 159 entry->e6.ipv6.proto = proto; 160 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; 161 break; 162 case NFPROTO_BRIDGE: 163 entry->ebt.ethproto = (__force __be16)proto; 164 entry->ebt.invflags = inv ? EBT_IPROTO : 0; 165 break; 166 case NFPROTO_ARP: 167 break; 168 } 169 par->entryinfo = entry; 170 par->target = target; 171 par->targinfo = info; 172 if (nft_is_base_chain(ctx->chain)) { 173 const struct nft_base_chain *basechain = 174 nft_base_chain(ctx->chain); 175 const struct nf_hook_ops *ops = &basechain->ops; 176 177 par->hook_mask = 1 << ops->hooknum; 178 } else { 179 par->hook_mask = 0; 180 } 181 par->family = ctx->family; 182 par->nft_compat = true; 183 } 184 185 static void target_compat_from_user(struct xt_target *t, void *in, void *out) 186 { 187 int pad; 188 189 memcpy(out, in, t->targetsize); 190 pad = XT_ALIGN(t->targetsize) - t->targetsize; 191 if (pad > 0) 192 memset(out + t->targetsize, 0, pad); 193 } 194 195 static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = { 196 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 }, 197 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 }, 198 }; 199 200 static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv) 201 { 202 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; 203 u32 l4proto; 204 u32 flags; 205 int err; 206 207 err = nla_parse_nested_deprecated(tb, NFTA_RULE_COMPAT_MAX, attr, 208 nft_rule_compat_policy, NULL); 209 if (err < 0) 210 return err; 211 212 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS]) 213 return -EINVAL; 214 215 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS])); 216 if (flags & NFT_RULE_COMPAT_F_UNUSED || 217 flags & ~NFT_RULE_COMPAT_F_MASK) 218 return -EINVAL; 219 if (flags & NFT_RULE_COMPAT_F_INV) 220 *inv = true; 221 222 l4proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); 223 if (l4proto > U16_MAX) 224 return -EINVAL; 225 226 *proto = l4proto; 227 228 return 0; 229 } 230 231 static void nft_compat_wait_for_destructors(struct net *net) 232 { 233 /* xtables matches or targets can have side effects, e.g. 234 * creation/destruction of /proc files. 235 * The xt ->destroy functions are run asynchronously from 236 * work queue. If we have pending invocations we thus 237 * need to wait for those to finish. 238 */ 239 nf_tables_trans_destroy_flush_work(net); 240 } 241 242 static int 243 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 244 const struct nlattr * const tb[]) 245 { 246 void *info = nft_expr_priv(expr); 247 struct xt_target *target = expr->ops->data; 248 struct xt_tgchk_param par; 249 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO])); 250 u16 proto = 0; 251 bool inv = false; 252 union nft_entry e = {}; 253 int ret; 254 255 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info); 256 257 if (ctx->nla[NFTA_RULE_COMPAT]) { 258 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); 259 if (ret < 0) 260 return ret; 261 } 262 263 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv); 264 265 nft_compat_wait_for_destructors(ctx->net); 266 267 ret = xt_check_target(&par, size, proto, inv); 268 if (ret < 0) { 269 if (ret == -ENOENT) { 270 const char *modname = NULL; 271 272 if (strcmp(target->name, "LOG") == 0) 273 modname = "nf_log_syslog"; 274 else if (strcmp(target->name, "NFLOG") == 0) 275 modname = "nfnetlink_log"; 276 277 if (modname && 278 nft_request_module(ctx->net, "%s", modname) == -EAGAIN) 279 return -EAGAIN; 280 } 281 282 return ret; 283 } 284 285 /* The standard target cannot be used */ 286 if (!target->target) 287 return -EINVAL; 288 289 return 0; 290 } 291 292 static void __nft_mt_tg_destroy(struct module *me, const struct nft_expr *expr) 293 { 294 module_put(me); 295 kfree(expr->ops); 296 } 297 298 static void 299 nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) 300 { 301 struct xt_target *target = expr->ops->data; 302 void *info = nft_expr_priv(expr); 303 struct module *me = target->me; 304 struct xt_tgdtor_param par; 305 306 par.net = ctx->net; 307 par.target = target; 308 par.targinfo = info; 309 par.family = ctx->family; 310 if (par.target->destroy != NULL) 311 par.target->destroy(&par); 312 313 __nft_mt_tg_destroy(me, expr); 314 } 315 316 static int nft_extension_dump_info(struct sk_buff *skb, int attr, 317 const void *info, 318 unsigned int size, unsigned int user_size) 319 { 320 unsigned int info_size, aligned_size = XT_ALIGN(size); 321 struct nlattr *nla; 322 323 nla = nla_reserve(skb, attr, aligned_size); 324 if (!nla) 325 return -1; 326 327 info_size = user_size ? : size; 328 memcpy(nla_data(nla), info, info_size); 329 memset(nla_data(nla) + info_size, 0, aligned_size - info_size); 330 331 return 0; 332 } 333 334 static int nft_target_dump(struct sk_buff *skb, 335 const struct nft_expr *expr, bool reset) 336 { 337 const struct xt_target *target = expr->ops->data; 338 void *info = nft_expr_priv(expr); 339 340 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) || 341 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) || 342 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info, 343 target->targetsize, target->usersize)) 344 goto nla_put_failure; 345 346 return 0; 347 348 nla_put_failure: 349 return -1; 350 } 351 352 static int nft_target_validate(const struct nft_ctx *ctx, 353 const struct nft_expr *expr) 354 { 355 struct xt_target *target = expr->ops->data; 356 unsigned int hook_mask = 0; 357 int ret; 358 359 if (ctx->family != NFPROTO_IPV4 && 360 ctx->family != NFPROTO_IPV6 && 361 ctx->family != NFPROTO_INET && 362 ctx->family != NFPROTO_BRIDGE && 363 ctx->family != NFPROTO_ARP) 364 return -EOPNOTSUPP; 365 366 ret = nft_chain_validate_hooks(ctx->chain, 367 (1 << NF_INET_PRE_ROUTING) | 368 (1 << NF_INET_LOCAL_IN) | 369 (1 << NF_INET_FORWARD) | 370 (1 << NF_INET_LOCAL_OUT) | 371 (1 << NF_INET_POST_ROUTING)); 372 if (ret) 373 return ret; 374 375 if (nft_is_base_chain(ctx->chain)) { 376 const struct nft_base_chain *basechain = 377 nft_base_chain(ctx->chain); 378 const struct nf_hook_ops *ops = &basechain->ops; 379 380 hook_mask = 1 << ops->hooknum; 381 if (target->hooks && !(hook_mask & target->hooks)) 382 return -EINVAL; 383 384 ret = nft_compat_chain_validate_dependency(ctx, target->table); 385 if (ret < 0) 386 return ret; 387 } 388 return 0; 389 } 390 391 static void __nft_match_eval(const struct nft_expr *expr, 392 struct nft_regs *regs, 393 const struct nft_pktinfo *pkt, 394 void *info) 395 { 396 struct xt_match *match = expr->ops->data; 397 struct sk_buff *skb = pkt->skb; 398 struct xt_action_param xt; 399 bool ret; 400 401 nft_compat_set_par(&xt, pkt, match, info); 402 403 ret = match->match(skb, &xt); 404 405 if (xt.hotdrop) { 406 regs->verdict.code = NF_DROP; 407 return; 408 } 409 410 switch (ret ? 1 : 0) { 411 case 1: 412 regs->verdict.code = NFT_CONTINUE; 413 break; 414 case 0: 415 regs->verdict.code = NFT_BREAK; 416 break; 417 } 418 } 419 420 static void nft_match_large_eval(const struct nft_expr *expr, 421 struct nft_regs *regs, 422 const struct nft_pktinfo *pkt) 423 { 424 struct nft_xt_match_priv *priv = nft_expr_priv(expr); 425 426 __nft_match_eval(expr, regs, pkt, priv->info); 427 } 428 429 static void nft_match_eval(const struct nft_expr *expr, 430 struct nft_regs *regs, 431 const struct nft_pktinfo *pkt) 432 { 433 __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr)); 434 } 435 436 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = { 437 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING }, 438 [NFTA_MATCH_REV] = NLA_POLICY_MAX(NLA_BE32, 255), 439 [NFTA_MATCH_INFO] = { .type = NLA_BINARY }, 440 }; 441 442 /* struct xt_mtchk_param and xt_tgchk_param look very similar */ 443 static void 444 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx, 445 struct xt_match *match, void *info, 446 union nft_entry *entry, u16 proto, bool inv) 447 { 448 par->net = ctx->net; 449 par->table = ctx->table->name; 450 switch (ctx->family) { 451 case AF_INET: 452 entry->e4.ip.proto = proto; 453 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; 454 break; 455 case AF_INET6: 456 if (proto) 457 entry->e6.ipv6.flags |= IP6T_F_PROTO; 458 459 entry->e6.ipv6.proto = proto; 460 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; 461 break; 462 case NFPROTO_BRIDGE: 463 entry->ebt.ethproto = (__force __be16)proto; 464 entry->ebt.invflags = inv ? EBT_IPROTO : 0; 465 break; 466 case NFPROTO_ARP: 467 break; 468 } 469 par->entryinfo = entry; 470 par->match = match; 471 par->matchinfo = info; 472 if (nft_is_base_chain(ctx->chain)) { 473 const struct nft_base_chain *basechain = 474 nft_base_chain(ctx->chain); 475 const struct nf_hook_ops *ops = &basechain->ops; 476 477 par->hook_mask = 1 << ops->hooknum; 478 } else { 479 par->hook_mask = 0; 480 } 481 par->family = ctx->family; 482 par->nft_compat = true; 483 } 484 485 static void match_compat_from_user(struct xt_match *m, void *in, void *out) 486 { 487 int pad; 488 489 memcpy(out, in, m->matchsize); 490 pad = XT_ALIGN(m->matchsize) - m->matchsize; 491 if (pad > 0) 492 memset(out + m->matchsize, 0, pad); 493 } 494 495 static int 496 __nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 497 const struct nlattr * const tb[], 498 void *info) 499 { 500 struct xt_match *match = expr->ops->data; 501 struct xt_mtchk_param par; 502 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO])); 503 u16 proto = 0; 504 bool inv = false; 505 union nft_entry e = {}; 506 int ret; 507 508 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info); 509 510 if (ctx->nla[NFTA_RULE_COMPAT]) { 511 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); 512 if (ret < 0) 513 return ret; 514 } 515 516 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv); 517 518 nft_compat_wait_for_destructors(ctx->net); 519 520 return xt_check_match(&par, size, proto, inv); 521 } 522 523 static int 524 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 525 const struct nlattr * const tb[]) 526 { 527 return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr)); 528 } 529 530 static int 531 nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 532 const struct nlattr * const tb[]) 533 { 534 struct nft_xt_match_priv *priv = nft_expr_priv(expr); 535 struct xt_match *m = expr->ops->data; 536 int ret; 537 538 priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL_ACCOUNT); 539 if (!priv->info) 540 return -ENOMEM; 541 542 ret = __nft_match_init(ctx, expr, tb, priv->info); 543 if (ret) 544 kfree(priv->info); 545 return ret; 546 } 547 548 static void 549 __nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr, 550 void *info) 551 { 552 struct xt_match *match = expr->ops->data; 553 struct module *me = match->me; 554 struct xt_mtdtor_param par; 555 556 par.net = ctx->net; 557 par.match = match; 558 par.matchinfo = info; 559 par.family = ctx->family; 560 if (par.match->destroy != NULL) 561 par.match->destroy(&par); 562 563 __nft_mt_tg_destroy(me, expr); 564 } 565 566 static void 567 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) 568 { 569 __nft_match_destroy(ctx, expr, nft_expr_priv(expr)); 570 } 571 572 static void 573 nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) 574 { 575 struct nft_xt_match_priv *priv = nft_expr_priv(expr); 576 577 __nft_match_destroy(ctx, expr, priv->info); 578 kfree(priv->info); 579 } 580 581 static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr, 582 void *info) 583 { 584 struct xt_match *match = expr->ops->data; 585 586 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) || 587 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) || 588 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info, 589 match->matchsize, match->usersize)) 590 goto nla_put_failure; 591 592 return 0; 593 594 nla_put_failure: 595 return -1; 596 } 597 598 static int nft_match_dump(struct sk_buff *skb, 599 const struct nft_expr *expr, bool reset) 600 { 601 return __nft_match_dump(skb, expr, nft_expr_priv(expr)); 602 } 603 604 static int nft_match_large_dump(struct sk_buff *skb, 605 const struct nft_expr *e, bool reset) 606 { 607 struct nft_xt_match_priv *priv = nft_expr_priv(e); 608 609 return __nft_match_dump(skb, e, priv->info); 610 } 611 612 static int nft_match_validate(const struct nft_ctx *ctx, 613 const struct nft_expr *expr) 614 { 615 struct xt_match *match = expr->ops->data; 616 unsigned int hook_mask = 0; 617 int ret; 618 619 if (ctx->family != NFPROTO_IPV4 && 620 ctx->family != NFPROTO_IPV6 && 621 ctx->family != NFPROTO_INET && 622 ctx->family != NFPROTO_BRIDGE && 623 ctx->family != NFPROTO_ARP) 624 return -EOPNOTSUPP; 625 626 ret = nft_chain_validate_hooks(ctx->chain, 627 (1 << NF_INET_PRE_ROUTING) | 628 (1 << NF_INET_LOCAL_IN) | 629 (1 << NF_INET_FORWARD) | 630 (1 << NF_INET_LOCAL_OUT) | 631 (1 << NF_INET_POST_ROUTING)); 632 if (ret) 633 return ret; 634 635 if (nft_is_base_chain(ctx->chain)) { 636 const struct nft_base_chain *basechain = 637 nft_base_chain(ctx->chain); 638 const struct nf_hook_ops *ops = &basechain->ops; 639 640 hook_mask = 1 << ops->hooknum; 641 if (match->hooks && !(hook_mask & match->hooks)) 642 return -EINVAL; 643 644 ret = nft_compat_chain_validate_dependency(ctx, match->table); 645 if (ret < 0) 646 return ret; 647 } 648 return 0; 649 } 650 651 static int 652 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, 653 int event, u16 family, const char *name, 654 int rev, int target) 655 { 656 struct nlmsghdr *nlh; 657 unsigned int flags = portid ? NLM_F_MULTI : 0; 658 659 event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event); 660 nlh = nfnl_msg_put(skb, portid, seq, event, flags, family, 661 NFNETLINK_V0, 0); 662 if (!nlh) 663 goto nlmsg_failure; 664 665 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) || 666 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) || 667 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target))) 668 goto nla_put_failure; 669 670 nlmsg_end(skb, nlh); 671 return skb->len; 672 673 nlmsg_failure: 674 nla_put_failure: 675 nlmsg_cancel(skb, nlh); 676 return -1; 677 } 678 679 static int nfnl_compat_get_rcu(struct sk_buff *skb, 680 const struct nfnl_info *info, 681 const struct nlattr * const tb[]) 682 { 683 u8 family = info->nfmsg->nfgen_family; 684 const char *name, *fmt; 685 struct sk_buff *skb2; 686 int ret = 0, target; 687 u32 rev; 688 689 if (tb[NFTA_COMPAT_NAME] == NULL || 690 tb[NFTA_COMPAT_REV] == NULL || 691 tb[NFTA_COMPAT_TYPE] == NULL) 692 return -EINVAL; 693 694 name = nla_data(tb[NFTA_COMPAT_NAME]); 695 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV])); 696 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE])); 697 698 switch(family) { 699 case AF_INET: 700 fmt = "ipt_%s"; 701 break; 702 case AF_INET6: 703 fmt = "ip6t_%s"; 704 break; 705 case NFPROTO_BRIDGE: 706 fmt = "ebt_%s"; 707 break; 708 case NFPROTO_ARP: 709 fmt = "arpt_%s"; 710 break; 711 default: 712 pr_err("nft_compat: unsupported protocol %d\n", family); 713 return -EINVAL; 714 } 715 716 if (!try_module_get(THIS_MODULE)) 717 return -EINVAL; 718 719 rcu_read_unlock(); 720 try_then_request_module(xt_find_revision(family, name, rev, target, &ret), 721 fmt, name); 722 if (ret < 0) 723 goto out_put; 724 725 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 726 if (skb2 == NULL) { 727 ret = -ENOMEM; 728 goto out_put; 729 } 730 731 /* include the best revision for this extension in the message */ 732 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid, 733 info->nlh->nlmsg_seq, 734 NFNL_MSG_TYPE(info->nlh->nlmsg_type), 735 NFNL_MSG_COMPAT_GET, 736 family, name, ret, target) <= 0) { 737 kfree_skb(skb2); 738 goto out_put; 739 } 740 741 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid); 742 out_put: 743 rcu_read_lock(); 744 module_put(THIS_MODULE); 745 746 return ret; 747 } 748 749 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = { 750 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING, 751 .len = NFT_COMPAT_NAME_MAX-1 }, 752 [NFTA_COMPAT_REV] = NLA_POLICY_MAX(NLA_BE32, 255), 753 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 }, 754 }; 755 756 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = { 757 [NFNL_MSG_COMPAT_GET] = { 758 .call = nfnl_compat_get_rcu, 759 .type = NFNL_CB_RCU, 760 .attr_count = NFTA_COMPAT_MAX, 761 .policy = nfnl_compat_policy_get 762 }, 763 }; 764 765 static const struct nfnetlink_subsystem nfnl_compat_subsys = { 766 .name = "nft-compat", 767 .subsys_id = NFNL_SUBSYS_NFT_COMPAT, 768 .cb_count = NFNL_MSG_COMPAT_MAX, 769 .cb = nfnl_nft_compat_cb, 770 }; 771 772 static struct nft_expr_type nft_match_type; 773 774 static bool nft_match_reduce(struct nft_regs_track *track, 775 const struct nft_expr *expr) 776 { 777 const struct xt_match *match = expr->ops->data; 778 779 return strcmp(match->name, "comment") == 0; 780 } 781 782 static const struct nft_expr_ops * 783 nft_match_select_ops(const struct nft_ctx *ctx, 784 const struct nlattr * const tb[]) 785 { 786 struct nft_expr_ops *ops; 787 struct xt_match *match; 788 unsigned int matchsize; 789 char *mt_name; 790 u32 rev, family; 791 int err; 792 793 if (tb[NFTA_MATCH_NAME] == NULL || 794 tb[NFTA_MATCH_REV] == NULL || 795 tb[NFTA_MATCH_INFO] == NULL) 796 return ERR_PTR(-EINVAL); 797 798 mt_name = nla_data(tb[NFTA_MATCH_NAME]); 799 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV])); 800 family = ctx->family; 801 802 match = xt_request_find_match(family, mt_name, rev); 803 if (IS_ERR(match)) 804 return ERR_PTR(-ENOENT); 805 806 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) { 807 err = -EINVAL; 808 goto err; 809 } 810 811 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL_ACCOUNT); 812 if (!ops) { 813 err = -ENOMEM; 814 goto err; 815 } 816 817 ops->type = &nft_match_type; 818 ops->eval = nft_match_eval; 819 ops->init = nft_match_init; 820 ops->destroy = nft_match_destroy; 821 ops->dump = nft_match_dump; 822 ops->validate = nft_match_validate; 823 ops->data = match; 824 ops->reduce = nft_match_reduce; 825 826 matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize)); 827 if (matchsize > NFT_MATCH_LARGE_THRESH) { 828 matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv)); 829 830 ops->eval = nft_match_large_eval; 831 ops->init = nft_match_large_init; 832 ops->destroy = nft_match_large_destroy; 833 ops->dump = nft_match_large_dump; 834 } 835 836 ops->size = matchsize; 837 838 return ops; 839 err: 840 module_put(match->me); 841 return ERR_PTR(err); 842 } 843 844 static void nft_match_release_ops(const struct nft_expr_ops *ops) 845 { 846 struct xt_match *match = ops->data; 847 848 module_put(match->me); 849 kfree(ops); 850 } 851 852 static struct nft_expr_type nft_match_type __read_mostly = { 853 .name = "match", 854 .select_ops = nft_match_select_ops, 855 .release_ops = nft_match_release_ops, 856 .policy = nft_match_policy, 857 .maxattr = NFTA_MATCH_MAX, 858 .owner = THIS_MODULE, 859 }; 860 861 static struct nft_expr_type nft_target_type; 862 863 static const struct nft_expr_ops * 864 nft_target_select_ops(const struct nft_ctx *ctx, 865 const struct nlattr * const tb[]) 866 { 867 struct nft_expr_ops *ops; 868 struct xt_target *target; 869 char *tg_name; 870 u32 rev, family; 871 int err; 872 873 if (tb[NFTA_TARGET_NAME] == NULL || 874 tb[NFTA_TARGET_REV] == NULL || 875 tb[NFTA_TARGET_INFO] == NULL) 876 return ERR_PTR(-EINVAL); 877 878 tg_name = nla_data(tb[NFTA_TARGET_NAME]); 879 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV])); 880 family = ctx->family; 881 882 if (strcmp(tg_name, XT_ERROR_TARGET) == 0 || 883 strcmp(tg_name, XT_STANDARD_TARGET) == 0 || 884 strcmp(tg_name, "standard") == 0) 885 return ERR_PTR(-EINVAL); 886 887 target = xt_request_find_target(family, tg_name, rev); 888 if (IS_ERR(target)) 889 return ERR_PTR(-ENOENT); 890 891 if (!target->target) { 892 err = -EINVAL; 893 goto err; 894 } 895 896 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) { 897 err = -EINVAL; 898 goto err; 899 } 900 901 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL_ACCOUNT); 902 if (!ops) { 903 err = -ENOMEM; 904 goto err; 905 } 906 907 ops->type = &nft_target_type; 908 ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize)); 909 ops->init = nft_target_init; 910 ops->destroy = nft_target_destroy; 911 ops->dump = nft_target_dump; 912 ops->validate = nft_target_validate; 913 ops->data = target; 914 ops->reduce = NFT_REDUCE_READONLY; 915 916 if (family == NFPROTO_BRIDGE) 917 ops->eval = nft_target_eval_bridge; 918 else 919 ops->eval = nft_target_eval_xt; 920 921 return ops; 922 err: 923 module_put(target->me); 924 return ERR_PTR(err); 925 } 926 927 static void nft_target_release_ops(const struct nft_expr_ops *ops) 928 { 929 struct xt_target *target = ops->data; 930 931 module_put(target->me); 932 kfree(ops); 933 } 934 935 static struct nft_expr_type nft_target_type __read_mostly = { 936 .name = "target", 937 .select_ops = nft_target_select_ops, 938 .release_ops = nft_target_release_ops, 939 .policy = nft_target_policy, 940 .maxattr = NFTA_TARGET_MAX, 941 .owner = THIS_MODULE, 942 }; 943 944 static int __init nft_compat_module_init(void) 945 { 946 int ret; 947 948 ret = nft_register_expr(&nft_match_type); 949 if (ret < 0) 950 return ret; 951 952 ret = nft_register_expr(&nft_target_type); 953 if (ret < 0) 954 goto err_match; 955 956 ret = nfnetlink_subsys_register(&nfnl_compat_subsys); 957 if (ret < 0) { 958 pr_err("nft_compat: cannot register with nfnetlink.\n"); 959 goto err_target; 960 } 961 962 return ret; 963 err_target: 964 nft_unregister_expr(&nft_target_type); 965 err_match: 966 nft_unregister_expr(&nft_match_type); 967 return ret; 968 } 969 970 static void __exit nft_compat_module_exit(void) 971 { 972 nfnetlink_subsys_unregister(&nfnl_compat_subsys); 973 nft_unregister_expr(&nft_target_type); 974 nft_unregister_expr(&nft_match_type); 975 } 976 977 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT); 978 979 module_init(nft_compat_module_init); 980 module_exit(nft_compat_module_exit); 981 982 MODULE_LICENSE("GPL"); 983 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 984 MODULE_ALIAS_NFT_EXPR("match"); 985 MODULE_ALIAS_NFT_EXPR("target"); 986 MODULE_DESCRIPTION("x_tables over nftables support"); 987