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